CIUDAD HIDALGO, Mexico — The first place many migrants sleep after entering Mexico from Guatemala is inside a large structure, a roof above and fenced sides on a rural ranch. They call it the “chicken house” and they can’t leave until they pay the cartel that runs it.

Migrant encounters at the U.S.-Mexico border have hit their lowest level in four years, but days before the U.S. election, where immigration is a key issue, migrants continue to pour into Mexico.

While U.S. authorities give much of the credit to their Mexican counterparts for stemming the flow to their shared border, organized crime maintains tighter control over who moves here than the handful of federal agents and National Guardsmen standing by the river.

Kidnapped migrants who pay the $100 ransom for their release are stamped to signal that they have paid. From January to August, right in this southernmost corner of Mexico, over 150,000 migrants were intercepted by immigration agents, which is considered a fraction of the flow.

Six migrant families interviewed by The Associated Press who had undergone an initial abduction and were held until they paid explained how it works. A Mexican federal official confirmed much of that. They all requested anonymity for fear of reprisals.

Mexican immigration agents encountered 925,000 undocumented migrants through August of this year, well above last year’s annual total and triple the 2021 total. Yet they have deported only 16,500, a fraction of previous years.

Pastor Heyman Vázquez, a priest in Ciudad Hidalgo along the Suchiate River that divides Mexico and Guatemala, sees it daily.

“They (the cartels) are the ones who say who makes it and who doesn’t,” Vázquez said. “The number of migrants they take every day is huge and they do it in front of the authorities.”

Pay to continue north

On Monday morning, Luis Alonso Valle, a 43-year-old Honduran traveling with his wife and two children, climbed off a raft lashed together with truck pipes and boards that had carried them across the Suchiate to Mexico.

They had not made it 50 meters towards Ciudad Hidalgo before three men approached on a motorcycle to tell them they could not continue walking. Then they saw journalists they left. The family looked scared.

In Ciudad Hidalgo’s central square, Valle asked for a van to take them the 23 miles (37 kilometers) to Tapachula, considered the main entry point for southern Mexico. The driver climbed aboard and whispered that journalists would stop recording. “They (organized crime) will stop me,” he said.

This is often how migrants arrive at the ranch. Taxi or van drivers working for the cartel take them there and hand them over. They are forced to sleep on the ground.

“There were more than 500 people there, some had been there for 10, 15 days,” said a Venezuelan woman who was released Sunday with her husband and two children. “Whoever doesn’t have money stays and whoever decides to pay leaves,” she said.

A 28-year-old baker from Ecuador was escorted to a bank to withdraw money to free himself, his wife, daughter and four other relatives. His family was held as insurance until he returned.

Once the payment is made, the migrants’ photos are taken and their skin is stamped.

Gunmen stop vans and taxis on their way to Tapachula and check for the stamps. Those without them are sent back. Migrants said that once they arrived in Tapachula, they were told to wash them off to avoid trouble with other gangs.

According to the non-governmental organization Fray Matias de Cordova in Tapachula, at least a third of the hundreds of migrants they have taken care of this year came stamped. Director Enrique Vidal Olascoaga said those who cannot pay are often sexually assaulted.

None of the families interviewed by the AP said they had been harmed.

The official with knowledge of the migrants’ statements to investigators said more than 100 migrants freed by security forces in Ciudad Hidalgo in September, as well as a group of several dozen migrants shot at by soldiers on Oct. 1, had gone through similar kidnapping and extortion scenarios.

Cartel controlled border

Organized crime’s tight control on Mexico’s southern border accompanies the growing violence generated by the struggle between the Sinaloa and Jalisco New Generation cartels. The state of Chiapas is just one of their battlegrounds, but it is the key to controlling smuggling routes for people, drugs and weapons from Central America. Migrants have become the most lucrative commodity, according to experts.

The increasingly aggressive presence of the cartels is becoming an obstacle for the organizations trying to help migrants. Earlier this month, gunmen killed an outspoken Catholic priest in Chiapas. And Vidal said that sometimes the groups prevent the migrants from receiving humanitarian aid.

President Claudia Sheinbaum has said the government is addressing the violence, but refuses to confront the cartels. She appears to be maintaining a tactic that began under former President Andrés Manuel López Obrador’s administration of cycling migrants from the north back down to the south, depleting their resources and keeping them far from the US border — exposing them to more kidnappings and extortion.

Ciudad Hidalgo Mayor Elmer Vázquez claimed he knows nothing about migrant safe houses operating in the area and said his city always takes care of migrants.

But Rev. Vázquez (no relation to the mayor), who has spent two decades defending migrants, said the prosecutor’s office, the National Guard, special prosecutors for crimes against migrants do nothing even when crimes are reported.

“They cooperate with organized crime and, of course, they make it look like they’re doing their job,” he said.

Race against time

In August, the U.S. government expanded access to CBP One, an online portal used to make appointments to request asylum at the border south of Chiapas. Mexico requested the move to ease the pressure migrants felt to travel north to get an appointment.

The Mexican government followed by opening “mobility corridors” to help migrants with CBP One bookings travel safely from southern Mexico to the US border. The appointments are only a first step, but most applicants will have to wait out the long process from within the United States

But from September 9 to October 11, Mexico’s national immigration agency said it had transported only 846 migrants from Tapachula to the northern border. Others traveling on their own have told of being blackmailed by Mexican authorities and kidnapped – again – by cartels near the northern border, forcing them to miss their appointments.

Donald Trump has said he would abolish CBP One and close other legal routes to enter the United States

In Tapachula on Tuesday, hundreds of migrants with confirmed CBP One appointments waited outside Mexican immigration agencies for permits that would allow them to travel north.

Jeyson Uqueli, a 28-year-old Honduran, had been sleeping outside the office to make sure he was first in line when it opened. He was traveling alone, but planned to reunite with his sister in New Orleans.

To have any chance of doing so, he must make it to the border between Brownsville, Texas and Matamoros, Mexico by Nov. 6 for his CBP One appointment. He planned to fly from Tapachula to the northern city of Monterrey and then take a bus to Matamoros.

He was nervous about being on time, but relieved to have the appointment, “because Donald Trump is going to come in and get rid of (them),” he said.

AP reporters Matías Delacroix in Tecun Uman, Guatemala, and Edgar Clemente in Tapachula, Mexico, contributed to this report.