Ayub Ibrahim had just walked out of the jungle. His feet still ached. A month earlier, he had left his home in Somalia, fleeing a civil war, he said, traveling first to Turkey, then Brazil and finally crossing on foot through a 66-mile expanse of wilderness known as the Darién Gap.

Resting in the sweltering San Vicente migrant camp in Panama with hundreds of other recent arrivals, he suddenly found himself surrounded by a half-dozen Americans with video cameras.

“Do you guys like Ilhan Omar?” one person asked. “What do you think about Joe Biden?”

Mr. Ibrahim, 20, answered the questions. He said he liked and admired Ms. Omar, the first Somali-American to serve in Congress. He doesn’t follow American politics, he added, but thinks Mr. Biden is a good president. When asked if Mr. Biden or former President Donald J. Trump would be better for immigrants, he chose Mr. Biden.

Later, Mr. Ibrahim would say he had felt ambushed and confused by the questions. He hadn’t intended to make a political statement.

But by then, it was too late.

One of his questioners, Laura Loomer, a right-wing activist and former Republican candidate for Congress, had already posted an edited video of the conversation online. It had rocketed around the internet, amassing nearly two million views on X.

The caption read: “Somali illegal aliens proclaim support for Ilhan Omar and Joe Biden inside Panama migrant camp!”

As immigration becomes a dominant issue in the 2024 presidential race, right-wing media has been awash in gritty and often deceptive videos of migrants emerging from the Darién Gap, a roadless stretch of Panamanian jungle that has become a bottleneck for thousands of people on their way to the United States.

The clips are presented as proof of what Republicans often describe as an “invasion” of Muslim terrorists, Chinese spies and Latin American criminals. Posted widely on social media, the videos blame President Biden for the migration and suggest, falsely, that Democrats are encouraging it to create new, illegal voters. International aid organizations are cast as profiteers making money off human misery.

The New York Times traced much of that content to the work of Michael Yon, a former Green Beret who over the past three years has become the go-to tour guide for right-wing journalists, politicians and social-media influencers wanting to see the Darién Gap firsthand.

Those travelers have included, along with Ms. Loomer, the Republican Representatives Tom Tiffany of Wisconsin and Burgess Owens of Utah, reporters, producers and podcast hosts for The Epoch Times, a right-wing newspaper, and correspondents for Real America’s Voice, the digital media company that hosts Stephen K. Bannon’s podcast.

Videos and other content made by the visitors have come to serve as a kind of B-roll footage accompanying conversations about immigration on Fox News, Tucker Carlson’s online show and even for Mr. Trump himself.

On Friday, the Republican presidential candidate reposted a video on Truth Social made by Ms. Loomer. It included several clips from her trip to Panama, including a snippet of her conversation with Mr. Ibrahim.

The Times followed one group as it toured camps on the edge of the Darién Gap, observing and recording as participants, interviewed migrants and shot video. The reporters, producers and influencers, gravitated toward migrants from Africa, China and the Middle East, barraging them with politically loaded questions.

Their posts amplified what they perceived as gotcha moments while dismissing answers that appeared to challenge their preconceptions.

When asked whether he had been given money by the United Nations or humanitarian groups, Mr. Ibrahim said he had not. He also said that as a Muslim he supported equal rights for women and was opposed to discrimination against gay people. Those portions of the interview were cut from the version posted online and missing from Ms. Loomer’s later accounts.

In an interview with a call-in talk show on Infowars, the far-right platform, Ms. Loomer questioned whether the Muslims she encountered, including Mr. Ibrahim, were “jihadists or people who have jihadist tendencies.”

Reached the next day on a bus bound for Costa Rica, Mr. Ibrahim said he regretted the experience. “She wanted to give a bad picture about immigrants to the world,” he said of Ms. Loomer. “Her questions weren’t fair.”

Clips of migrants in Panama have become weapons in the information battle being waged over immigration, experts said. The content, looped again and again online, is highly effective, particularly in creating the perception of the threat of violence, said Guadalupe Correa-Cabrera, a political science professor at George Mason University who has studied social media’s impact on immigration.

The images, she noted, tend to focus on young men while excluding women and children, who might generate more sympathetic responses. The migrants are often referred to as “military-aged men” and “invaders” and their claims of political or religious persecution at home are often dismissed as scripted falsehoods.

“This is straight from the textbook for how you build a narrative,” Ms. Correa-Cabrera said.

The influencers and media figures on the tours argue that they are shedding light on a crisis that mainstream outlets either downplay or refuse to cover. Ms. Loomer described herself as a journalist. “My reporting was so powerful,” she said.

The focus on Muslim and Chinese migrants may create a distorted impression. Roughly 90 percent of the 520,000 people who crossed through the Darién Gap last year were South Americans and Caribbeans, according to the Panamanian government. The vast majority of that group comes from Venezuela, Ecuador and Haiti, countries experiencing economic and political upheaval.

The number of migrants from Africa, China and the Middle East coming through the Darién Gap has boomed in the past two years, but is less than 8 percent of the total. Panama screens migrants from those regions for potential criminal or terrorist connections. So far, the terrorism threat they might represent is theoretical. Several academic studies have found no correlation between immigration and acts of terror, a review by the Council on Foreign Relations published last fall found.

Critics warn that inflammatory coverage of these complex problems only serves to aggravate a humanitarian crisis.

“The misrepresentation of the migrants crossing the gap as invaders or illegals puts their life at risk,” said Sandie Blanchet, UNICEF’s representative in Panama. “It can justify harsh treatment and even violence against them.”

Inside an ‘Invasion Investigation’

On a steamy February afternoon outside a government migrant camp on the edge of the Chucunaque River, Mr. Yon escorted a reporter and photographer from The Epoch Times up a hill, pausing to gesture at three weary Venezuelan migrants limping across a bridge.

“If we lose this, it is over. You know what I mean? The United States is done,” he said.

In some circles on the right, an invitation to tour with Mr. Yon has become something of a golden ticket, promising access on the ground and publicity upon return.

A swaggering Special Forces veteran, Mr. Yon has long had a knack for getting attention. In his autobiography, he recounts killing a man with his bare hands in a bar fight. (Charges against him were eventually dropped.) He later made headlines as a frontline blogger and photographer at the height of the wars in Iraq and Afghanistan.

He has since immersed himself in right-wing politics around the globe. In 2014, he was recruited by Japanese activists to dispute the long-established existence of “comfort women,” the Korean women forced into sexual slavery during World War II. More recently, he joined Dutch farmers protesting environmental reform, claiming it was part of a plan to replace the country’s population with immigrants.

On Jan. 6, 2021, he was outside the U.S. Capitol and later falsely said that the rioters were spurred on by “agent provocateurs” connected to Antifa.

That year was a turning point for migration through the Darién Gap, an inhospitable stretch of mountainous wilderness that is riddled with poisonous snakes and roving gangs of criminals. What had been a trickle of just a few thousand people crossing the gap each year gushed to 133,000, an increase fueled largely by Haitians fleeing economic chaos.

Mr. Yon arrived in Panama that February and began his tours shortly after — including one with Mr. Tiffany and Mr. Owens. In total, he estimates he has brought as many as 60 people to see the camps in person, and tries to remain behind the scenes. “I just want people to see for their own self and make their mind up,” he said.

But he often portrays himself as an expert, sitting for frequent interviews with the conspiracy theorist Alex Jones, as well as in a 2022 video called “Alien Invasion” produced by Representative Andy Biggs, a Republican of Arizona.

Mr. Yon says he makes no profit from the trips. Guests cover their own expenses, including $35-a-night rooms at a modest hotel just steps from a migrant camp. He also raises money online: A crowdsourced fund-raiser begun in February to pay for a “Darien Gap Migrant Invasion investigation mission” has raised just shy of $13,000.

Ms. Loomer, for her part, initially sought to raise $14,500 to fund a seven-day trip but blew past that goal, extending her stay by three days and raising close to $28,000.She said she did not make a profit.

Last week, she started a new online fund-raiser, seeking $100,000 to pay for a film about her experiences in Panama. Its title, she said, will be “The Great Replacement,” a reference to the conspiracy theory that Democrats are encouraging immigration in a scheme to replace white voters.

A Narrative Takes Hold

Mr. Yon and his tours often take aim at the humanitarian organizations at work in the area, reserving particular ire for one United Nations agency — the International Organization for Migration. The groups, they say, incentivize migration by providing health care, psychological support and nutrition both before and after migrants make the journey.

That aid is paid for by government contributions and private donations, funds that Mr. Yon calls “profits” that motivate the organizations to encourage more migration.

Diego Beltran, interim director for Central and North America and the Caribbean for the migration organization, disputed the characterization, noting that the U.N. doesn’t profit from its activities and that it works to find alternatives to migration. The agency has helped more than four million migrants settle legally in South America rather than move north to the U.S., he said.

“There is a great deal of disinformation in this area,” Mr. Beltran said. “It’s clear that migration is increasingly a political issue in many countries. But we don’t agree with efforts to stigmatize migrants and increase xenophobia.”

Another target is HIAS, formerly known as the Hebrew Immigrant Aid Society, a U.S. nonprofit that provides services, including legal aid and mental health, to migrants. Mr. Yon’s tours have made an issue of the large maps of the region it posts on some of its facilities in Panama, claiming they encourage people to make the trek.

HIAS officials say the maps, which do not detail specific routes through the gap, are meant to help migrants find aid stations.

“We certainly don’t encourage migration,” said Mark Hetfield, the HIAS president. “All we’re offering is a way to assist those who arrive there.”

Mr. Hetfield said many of the criticisms of his group were grounded in antisemitism, noting that the man who murdered 11 people at a Pittsburgh synagogue in 2018 had frequently posted rants about the group. “HIAS likes to bring invaders in that kill our people,” the killer posted online just hours before the attack.

Mr. Yon has also claimed, without evidence, that the group is helping dangerous migrants enter the U.S. “They’re going to scream ‘Allahu akbar! And they’re going to shoot” them, he said, using an obscenity, at an anti-immigration rally last month near Eagle Pass, Texas. “And they’re coming across the border and it’s being funded with Jewish money.”

There is some evidence that the narrative cultivated by Mr. Yon and others in his groups is having an impact. This month, after influencers who visited the region posted dozens of complaints online about maps hung by international groups, the director of Panama’s National Migration Service raised a similar concern, calling it “irresponsible.”

HIAS has since removed some of its maps in the region, saying it did so for “security reasons.”

‘Angels of the Jungle’

Mr. Yon has forged close ties with the Panamanian government, and particularly its border patrol. His groups have frequently received unrestricted access to migrant facilities, while mainstream journalists are often prohibited.

A key to that access is Oscar Ramirez, a Mexican activist and correspondent for Real America’s Voice, who since early last year has worked with Mr. Yon in Panama as a fixer and translator. With a military bearing, he greets border officers with hugs at checkpoints and receives armed escorts on treks through the Darién Gap itself. And while he is quick to rail against international groups, he calls the border patrol “angels of the jungle” in social media posts and news reports.

At a recent security forum in Panama City, Maj. Nelson Moreno, a border patrol protocol officer, described Mr. Ramirez as “an integral part of our border DNA.”

Two days earlier, a border guard stopped Times journalists from traveling to an Indigenous village where Mr. Ramirez and Mr. Yon, along with roughly a dozen American influencers, were filming migrants.

Although there were no other witnesses to the episode, Ms. Loomer discussed it in an interview on Infowars, the right-wing website founded by Mr. Jones, the following day, saying the agency considered the Times journalists a “security risk.”

Mr. Yon later said he had learned about the episode from sources in the region. You can’t make a move in the Darién Gap, he said in an interview with The Times, “without me hearing about it.”

Constant Content Creation

Over 10 days, Ms. Loomer visited four migrant centers, navigated rivers in motorized canoes, rode through the Panama Canal, and posted nearly 100 times on X about the trip. One video has over 4.5 million views and was shared by Michael T. Flynn, Mr. Trump’s former national security adviser.

“We are being invaded,” Ms. Loomer said in the clip, as she boarded a bus with migrants. “We are being replaced and it’s no accident it’s happening in an election year.”

In the crowded San Vicente camp, Yazdan Faramehr, a 29-year-old bodybuilder from Iran who speaks good English, was encircled by Americans clutching video cameras. As they peppered him with questions, he told them he was hoping to get a fresh start in Los Angeles’s large Persian community.

But Mr. Faramehr grew uncomfortable when Ms. Loomer, who once identified herself as a “proud Islamophobe,” but now rejects the label, began asking about Iranians coming the U.S. to “commit acts of Islamic terrorism.” Worried about drawing unwanted attention or putting his family at risk, he asked that the group not use his image.

Mr. Yon posted a clip on X anyway. It drew dozens of replies from people speculating that Mr. Faramehr, who said he worked in human resources in Tehran, was a dangerous intruder with a secret agenda.

Reached as he traveled north from Panama, Mr. Faramehr gave The Times permission to use his photo. He said he thought it was fair of Mr. Yon’s tour to “criticize their country’s immigration system” but felt like they were trying to trap him.

“To be honest,” he said, “I wish I never talked to them.”

President Biden will propose a budget Monday packed with tax hikes on corporations and high earners, new spending on social programs and a wide range of efforts to combat high consumer costs such as housing and college tuition.

The new spending and tax increases included in the 2025 budget have virtually no chance of becoming law this year as Republicans control the House and outright oppose Biden’s budget agenda. Last week, Republicans in the House of Representatives adopted a budget proposal outlining their priorities, which are far removed from what Democrats have asked for.

Instead, the document will serve as a draft of Mr. Biden’s policy platform as he seeks reelection in November, along with a series of contrasts intended to distinguish him from his presumptive Republican opponent, former President Donald J. Trump.

Mr. Biden has been trying to regain his strength on the economic front from voters who have given him low marks amid soaring inflation. This budget aims to portray him as a champion of greater government support for workers, parents, manufacturers, retirees and students, and of the fight against climate change. Biden’s budget proposes to more than offset the costs of these priorities through higher taxes on big corporations and the wealthy. The president is already trying to portray Trump as the opposite: a supporter of further tax cuts for corporations.

“A fair tax code is how we invest in the things that make this country great: health care, education, defense and so much more,” Biden said during his State of the Union address on Thursday.

Later in the speech, in a call-and-response with Democrats in the House, Mr. Biden added: “Folks at home, does anyone really think the tax code is fair? Do you really think the rich and big corporations need another $2 trillion tax break? Certainly not. I will continue to fight hard to make it fair.”

Polls show Americans are dissatisfied with Mr. Biden’s handling of the economy and favor Mr. Trump’s approach to economic issues. But Mr. Biden has been steadfast in his core economic policy strategy, and the budget is not expected to deviate from that plan.

White House officials said in previewing the budget release that Biden would propose about $3 trillion in new measures to reduce the budget deficit over the next decade. That’s in line with his budget proposal last year, which reduced deficits by raising taxes on corporations and the wealthy and having the government negotiate more aggressively with pharmaceutical companies to reduce spending on prescription drugs.

Mr. Biden will again call for an increase in the corporate tax rate from 21 percent to 28 percent, the level Trump set in the tax bill he signed in late 2017. Mr. Biden will also propose raising a new minimum tax on large corporations and quadrupling a tax on stock buybacks, among other efforts to raise more revenue from companies and individuals making more than $400,000 a year.

These cuts would build on the discretionary spending limits that Biden and Republicans in Congress agreed to last year to resolve an impasse over raising the nation’s borrowing limit. But even if Congress were to agree to all of Biden’s $3 trillion proposals, the deficit would still average about $1.7 trillion per year over the next decade, based on forecasts from the nonpartisan Congressional Budget Office.

Republicans in the House of Representatives released a budget last week that aims to reduce deficits much faster – bringing the budget to a balanced position by the end of the decade. Their savings were based on economic growth forecasts well above the expectations of mainstream forecasters, along with steep and often unspecified budget cuts.

The nonpartisan Committee for a Responsible Federal Budget called the Republican plan “unrealistic in its assumptions and results.” Last year, the same group said Biden’s budget “fell far short of the deficit reduction needed to put the nation on a sustainable fiscal path.”

Mr. Biden and his aides have repeatedly said they are confident the projected deficits in his budgets will not hurt the economy. Rather than focusing on more aggressive deficit reduction, as previous Democratic presidents have done after losing control of a chamber of Congress, Mr. Biden has focused on the need for new spending programs and targeted fiscal stimulus.

White House officials said the new budget proposal would continue that trend. It will include a national paid leave program for workers. It will restore an expanded child tax credit that Mr. Biden temporarily created in his $1.9 trillion 2021 economic stimulus law, which helped significantly reduce child poverty in the span of a year before it expired.

It will also include new efforts to help Americans grapple with high costs. That issue has dogged Mr. Biden among voters since inflation rose to the highest level in four decades on his watch, even as price increases have cooled over the past year. Mr. Biden previewed many of these efforts in his State of the Union address, including new tax breaks for certain homebuyers and expanded help for people to get health insurance through the Affordable Care Act.

Mr. Biden will also call for new efforts to improve the solvency of Social Security and Medicare, but not the full overhaul of Social Security that he previewed in the 2020 campaign but failed to deliver during his term realised. He will oppose benefit cuts for the programs, officials said, suggesting he favors a familiar strategy to strengthen them: raising taxes on high earners.

Migration to the United States through the dangerous jungle known as the Darién Gap returned to normal on Friday, with hundreds of people from Venezuela, Ecuador and beyond entering the jungle after a lull of about five days during which migrants could not begin the trek .

The pause in this ever-increasing migration flow was the result of an arrest operation led by the Colombian prosecutor’s office, in which two captains who steered boats full of migrants into the jungle were taken into custody, where the prosecutor’s office says they remain. The office said the captains transported the individuals illegally, in part because the migrants did not have proper documentation.

The captains worked for two boat companies – Katamaranes and Caribe – that for years have played a vital role in transporting migrants from the northern Colombian community of Necoclí for about two hours across a gorge to the jungle entrance, where they then have to cross . reaching Central America and eventually the United States. The boat companies have done this openly – something extensively documented by The New York Times – and the arrests appeared to signal a change in policy by Colombian authorities.

But in retaliation for the arrests, boat companies halted transport, and the number of migrants waiting in Necoclí and another exit town, Turbo, quickly grew to several thousand people. That posed a huge challenge for both cities, which do not have the resources or infrastructure to house and feed so many people for long periods of time.

The arrests of the boat operators came after months of pressure from the United States on the Colombian government to do more to limit or stop migration through the Darién. In a recent interview, Hugo Tovar, a Colombian prosecutor, said his office, with the help of the United States, was working diligently to investigate and arrest human traffickers.

On Friday, Johann Wachter, secretary of the municipal government of Necoclí, said the boat companies decided to restart their operations after a meeting between representatives of the boat companies, local governments, Colombia’s National Migration Agency and other agencies, including someone from the U.S. Embassy. in Colombia.

At the meeting, Mr. Wachter said, representatives of Colombia’s migration agency assured boat companies that “there would be no problem” as long as the migrants they were transporting “comply with the requirements.” In this case, Mr Wachter said, any person wanting to cross the jungle would have to fill out a form on a mobile phone application called Secure Transit.

(Officials from the U.S. Embassy and Colombia’s migration agency did not immediately respond to requests for comment.)

The Darién jungle is the strip of land that connects South and North America. It must be crossed to get to the United States on foot from South America. Although rarely crossed, it has become a major artery for migrants in the past three years, with almost a million people risking the journey as of 2021. This has been a huge challenge for President Biden, who has seen record numbers of arrivals in the United States. southern border during his presidency.

The fallout in Necoclí from the boat companies’ decision to halt operations after just two arrests shows how difficult it is for U.S. and Colombian officials to stop the multimillion-dollar company that moves people in northern Colombia. Any attempt to stop this through law will likely have unintended consequences, including the crowding of thousands of people into poor Colombian cities unable to care for them.

Mr Wachter, for his part, called the restart of migrant transport a positive move. “Our capacity is limited,” he said, “so this gives us a lot of peace of mind.”

When the Supreme Court struck down a core part of the Voting Rights Act in 2013, Chief Justice John G. Roberts Jr. argued. that some of the law’s protections against racial discrimination were no longer necessary.

He wrote that the once troubling turnout gap between white and black voters in areas with a history of electoral discrimination had largely disappeared, and that “the conditions that originally justified civil rights law’s attention to these places, especially in the South, existed not anymore.

But a new, yearlong study from the Brennan Center for Justicea nonpartisan think tank focused on democracy and voting rights issues suggests otherwise.

Before the decision, counties with a history of racial discrimination in elections had to get permission from the Justice Department before changing voting laws or procedures. This was known as “preclearance” under Section 5 of the Voting Rights Act, and it was the Supreme Court’s 2013 decision in Shelby County v. Holder that effectively overturned this part of the law.

Since that decision, the gap in turnout rates between white and nonwhite voters has grown “nearly twice as fast in previously covered jurisdictions as in other parts of the country with similar demographic and socioeconomic profiles,” Brennan’s study found .

The “racial turnout gap” refers to the difference in the percentage of eligible white and non-white voters who voted in a given election. This gap is closely watched by voting rights groups and civil rights leaders as an indication of potentially harmful laws or procedures that could have oppressive effects on communities of color.

According to the group’s report, the turnout gap between black and white voters in former Section 5 counties has grown by 11 percentage points between 2012 and 2022 since the Shelby decision. The study drew on nearly a billion voter records to estimate that if the decision never happened, the white-black turnout gap would have nevertheless increased, but by only six percentage points.

While that difference may seem small, the study’s authors argue that such differences are “potentially enormous” in modern politics: Since 2012, at least 62 elections for the Senate, governor and president in states with Section 5 counties have been decided by fewer than five percentage points.

“From a moral perspective, it obviously matters, but it also matters because the margins are significant, especially given the close elections across the country,” said Kareem Crayton, senior director of voting rights and representation at the Brennan Center.

After the Shelby decision, state lawmakers across the country passed a series of new voting restrictions, including new voter ID laws, and purged hundreds of thousands of names from voter rolls. But turnout is affected by a number of things, including the time it takes to vote and other motivating factors like close races or polarizing candidates, making it an inaccurate metric to measure the impact of those laws, many argue. And the impact of the Supreme Court’s 2013 decision was far greater than just new voting laws; Any number of voting procedures, such as changing polling places or purging voter rolls, were no longer subject to federal approval.

“Do we know that Shelby County has changed its election laws? Yes,” said Bernard Fraga, professor of political science at Emory University in Atlanta. “What impact does that have on turnout? Turnout is downstream, is affected by election laws, is affected by people’s response to election laws, how competitive elections are – a number of other factors that make it difficult to look at turnout and say that we now have the impact of the Shelby can assess the province’s decision.”

Most attempts to quantify the racial turnout gap rely on statistics such as censuses and political surveys such as exit polls. The Brennan Center study relied on those voter files — detailed data on voters’ histories and habits — from every federal election since 2008 to assess the gap, claiming that an analysis of that data provides a more complete picture.

The authors noted that statistical limitations prevented them from estimating a total number of votes lost as a result of the Shelby decision.

More broadly, the report’s findings support what voting rights activists and experts say is an alarming turning point in the country’s broader democratic foundations. After the Voting Rights Act and the civil rights movement of the 1960s, nonwhite voter participation grew for decades. That is no longer the case.

The survey shows that there is a significant racial turnout gap across the country, outside of counties previously under Section 5. In the 2020 election, 9.3 million more people would have voted if non-white voters had participated at the same rate as white voters. In the 2022 midterm elections, that total would have been 13.9 million ballots.

The gap persisted between education and income lines. Although turnout is declining across racial and ethnic lines in lower-income communities, poorer white voters are still more likely to turn out than their non-white peers, according to the study.

The widening turnout gap is a “major problem,” said Jake Grumbach, a policy professor at the University of California, Berkeley. “The democratic institutions in the US have become healthier since 1965. And this is the first time the trend has actually reversed in the post-civil rights era. And so I think that’s the damaging point.”

There are many other factors that contribute to election turnout. Still, the total number of “missing” votes is most likely large, the study says.

“By the 2022 midterm elections, the Shelby County Effect cost hundreds of thousands of ballots cast by voters of color in previously covered counties in each federal general election,” Mr. Crayton said. “And we know that even a fraction of that number can make a difference in elections or in awarding electoral votes to a state.”

Migration into the United States through the dangerous jungle passage known as the Darién Gap has been halted, at least temporarily, following the arrest of two boat captains who work for companies that play a vital role in transporting migrants into the jungle.

According to the mayor of Necoclí, boat companies have suspended the crossing of migrants from two towns in northern Colombia, Necoclí and Turbo, to the entrance of the Darién Forest, leaving about 3,000 migrants stranded in those communities.

Colombian law enforcement action in the region will certainly be closely watched by U.S. officials: The Biden administration has been putting pressure on Colombia for months to try harder to prevent people from using the Darién as a path to the United States.

The boat route is the main route to the Darién Gap, a strip of land connecting South and North America that was once rarely crossed, but in recent years has become one of the most important and busiest migration routes in the hemisphere.

Authorities at the end of the route in Panama say nearly a million people have crossed the Darién since 2021, helping to fuel an immigration crisis in the United States.

The Colombian navy last week seized two boats from the two companies, Katamaranes and Caribe, which transported a total of 151 migrants from Necoclí to the jungle, according to the Colombian prosecutor’s office.

Officials determined that the migrants were being transported illegally, arrested the two boat captains and took control of both boats.

The arrests mark a major change in strategy by Colombian authorities, who for months have allowed boat operators to openly ferry migrants from Necoclí across the Gulf of Urabá to the towns of Acandí and Capurganá, where people venture into the jungle.

In an interview on Wednesday, Necoclí Mayor Guillermo Cardona said the boat companies, which operate large fleets and have multiple captains, had halted their activities in recent days “as a form of protest” against the arrests.

Boat operators have become key players in a multimillion-dollar migration business that has blossomed in northern Colombia.

In September, The New York Times reported that this company was run by local politicians and economic leaders, including Katamaranes’ manager, who was a mayoral candidate in Necoclí at the time. (The manager did not win and was not among those arrested.)

U.S. officials have personally asked Colombian officials since at least October to investigate the boat operators.

In a recent interview, a leading Colombian prosecutor, Hugo Tovar, said his office was working “hand in hand” with the United States on human trafficking through Colombia and the Darien. Two U.S. agencies, Homeland Security and Immigration and Customs Enforcement, provided training and shared information to assist with investigations, he added.

Necoclí is a seaside resort with limited resources and infrastructure, and has been overwhelmed by migrants in recent years.

It is unclear how long the boat companies will cease operations. Hundreds of migrants have been arriving a day in recent months, and if the protest continues, the number of people stranded in tents on the city’s beaches is likely to increase rapidly, pushing water and sanitation facilities beyond their breaking points.

This could put pressure on the Colombian government to ease any future arrests of boat operators, as the government has limited capacity to provide assistance to large numbers of people who could become stuck at the northern border.

Still, Mr. Tovar said his office remained committed to investigating human trafficking, calling it “a hemisphere-wide issue.”

Mr. Cardona, the mayor, said he was appealing to the national government for help for the hundreds of migrants who now have nowhere to go. “This is an SOS,” he said.

Immigration through the Darien has proven to be a huge challenge for the Biden administration, especially ahead of the 2024 presidential race.

President Biden and his almost certain Republican rival Donald J. Trump are both scheduled to appear Thursday in different parts of Texas near the southern border.

In 2021, just over 130,000 people passed through the jungles of Darién on their way to the United States. In 2022 there were almost 250,000. More than 500,000 people crossed the Darién last year, setting a record number of arrivals at the U.S. border.

Mr. Biden has tried to deter this flow by expanding legal migration routes and stepping up deportation efforts at the border.

But these measures have had only a limited effect.

On February 28, Panama authorities said that more than 72,000 people had crossed through Darien this year – a 35 percent increase over the number of people crossing the border in the first two months of last year.

The largest number of migrants came from Venezuela, where activists’ hopes that the authoritarian government would allow democratic elections this year have faded in recent months. The second most came from Ecuador, where the poor security situation has worsened this year. The next three major countries of origin are Haiti, Colombia and China.