MONTERREY, Mexico — For years, the Esquivel family watched as neighbors fled the violence of San Salvador for the long journey north to the U.S. border.

But it wasn’t until July, after a local gang started murdering their relatives in broad daylight and the threats against their children grew more specific, that the family of four decided to join the migration. They traveled 2,000 miles to the Rio Grande, crossed by raft in the middle of the night, and landed in the small town of Roma, Tex.

There, they turned themselves in to the U.S. Border Patrol and began the process of filing for asylum.

Under the Trump administration policy called the Migrant Protection Protocols, the family Victor Esquivel, his wife, Maria, and their sons Anderson, 10, and Ryan, 4 — were sent back to the Mexican state of Tamaulipas to await their first hearing, scheduled for October.

What happened next confirmed the worst fears of migrant advocates, lawyers and Mexican officials. All argued that the expansion last month of MPP — the so-called Remain in Mexico policy — into one of Mexico’s most dangerous states was a disaster in the waiting.

On July 24, U.S. officials dropped the family off at the international bridge that connects Laredo, Tex., to the city of Nuevo Laredo, in Tamaulipas. They were given a pile of immigration paperwork and escorted to the parking lot of the Mexican immigration office, 20 yards south of the Rio Grande.

For the first three nights, they slept on the ground outside the office in the 100-degree heat. Exhausted and hungry, they arranged through a family friend to pay for a small apartment where they could wait for their October hearing.

On July 27, Victor and Maria walked outside the immigration office in the early afternoon, they said, holding the hands of their two sons. They made it two blocks, toward a car that was supposed to take them to the apartment. Then a truck pulled up next to them and a group of men jumped out, screaming at them.

“They yelled, ‘Get into the truck!’” Victor said. “It all happened really quickly.”

Since “Remain in Mexico” began in February, Human Rights First, an advocacy organization, has catalogued 110 “cases of rape, kidnapping, sexual exploitation, assault, and other violent crimes” against asylum seekers sent back to Mexico under the program, according to a report released Thursday.

Since the policy was expanded from the Mexican states of Baja California and Chihuahua to the more dangerous state of Tamaulipas last month, several asylum seekers have been kidnapped, often from public places. Some were held during the same period as the Esquivel family, but apparently in different homes, potentially by different groups.

The U.S. State Department this year gave Tamaulipas its most severe travel warning — Level Four: Do Not Travel — placing it at the same level as Syria and Afghanistan.

“Armed criminal groups target public and private passenger buses as well as private automobiles traveling through Tamaulipas, often taking passengers hostage and demanding ransom payments,” the State Department advised. “Federal and state security forces have limited capability to respond to violence in many parts of the state.”

“This is exactly what we were worried about,” said Salvador Rosas, who represents Tamaulipas in Mexico’s Congress. “We can’t guarantee their security there. There are going to be more kidnappings. There are going to be migrants killed.”

Two Venezuelan and one Cuban asylum seeker who were sent back to Nuevo Laredo by U.S. officials in July also told The Washington Post of their ordeal.

They were at a bus station when two men approached them, asked where they were from and where they were going. Within minutes, and without weapons, the men physically forced the Venezuelans into a car.

They were taken to a small house and told to put all their possessions on a table. Three migrants from Nicaragua and Honduras were already there, according to the Venezuelans. They said they had also been kidnapped that morning.

“I just started crying,” one of the Venezuelan men said. They spoke on the condition of anonymity for fear of reprisals.

The Cuban man and one of the Venezuelans scraped together around $400 in cash from an ATM and were released six hours later. The other Venezuelan was held for four more days.

Tamaulipas officials and immigration attorneys in South Texas say roughly 3,000 migrants have been sent back to the state in the past month. To safeguard them, Mexico’s immigration agency is offering to take migrants three hours by bus to the city of Monterrey, which is considered to be safer than Nuevo Laredo. But that takes them farther away from their Texas-based immigration lawyers and the U.S. cities where their court dates are scheduled.

The Trump administration has supported “Remain in Mexico” as a way to reduce the number of asylum seekers who wait in the United States for their asylum hearings. Because of the backlog in asylum courts, many of them wait for years, with permission to work.

The U.S. Department of Homeland Security did not respond to multiple inquiries about the kidnappings in Tamaulipas. But at least one DHS representative in South Texas said privately that they had been informed about such cases through contacts in Mexico.

The Esquivels say they were taken to an abandoned house where migrants from Cuba and Guatemala were also being held. They were led to a room without furniture and told to sit on the ground.

“We never saw any guns,” Maria said. “But they told us that if we weren’t obedient, they would hurt us.”

The kidnappers took their phones and used them to send messages to Esquivel’s relatives in El Salvador and Wisconsin demanding $7,500 per person. The family shared copies of those text and voice messages with The Post. They also shared messages that they sent to Salvadoran consulates in Mexico and the United States pleading for help. The Post was in touch with Esquivel’s relatives for the duration of the kidnapping.

The Esquivels were moved between three different houses in and around Nuevo Laredo. They were held with about 10 different migrants, including a Nicaraguan family with two small children, Victor said. That family said they, too, had been returned to Mexico to wait for their asylum hearings.

The father of the Nicaraguan family wrote the telephone number of relatives back home on the front page of Victor’s Bible, in case he was released first.

“Call them please,” the father wrote in Spanish.

For the first few days, the kidnappers gave the Esquivels tacos filled with mushrooms and potatoes. They give the children paper to fold into airplanes. But after a week, they grew more threatening. The two boys complained that they were hungry. Ryan, 4, started crying.

One of the kidnappers texted Victor’s sister, a teacher in El Salvador.

“If you don’t pay us we’re going to stop giving them food,” he wrote.

“I’m going to send you the name and you’re going to deposit the money there,” the kidnapper told Jacky, Victor’s sister in a conversation that she recorded.

Her voice quivered when she responded, which can be heard in the recording.

“We’re going to keep looking for the money,” she said. “We’re trying.”

The kidnappers gave Jacky 16 bank accounts and told her to deposit $500 in each, to start.

She made two deposits of $467 in two different accounts and said it was all she had. She showed the transfer receipts to The Post, and a phone number one of the kidnappers used to contact her.

The Post called the number. The man who responded said he was not aware of any kidnapping.

A Salvadoran official in Mexico said the country is trying to inform its citizens of how dangerous Tamaulipas is for migrants. El Salvador’s government is investigating what happened to the Esquivels.

“What’s so dramatic about these cases is that these people made it to the United States. They were only kidnapped when they were returned,” said the official, who spoke on the condition of anonymity because he was not authorized to speak publicly about the kidnapping.

On the morning of their 11th day being held, Victor started weeping. He begged the kidnappers to release the family. By then, the two wire transfers had come through. The kidnappers herded the family into the truck, again, and dropped them off two blocks away from the bus station. Victor used $60 he had kept in his sock to buy bus tickets to Monterrey.

“I still can’t believe they let us leave,” he said in a Monterrey hotel. “I thought they were going to kill us.”

Relatives in El Salvador paid for their flight back to San Salvador. Victor said the family isn’t sticking around for their U.S. asylum claim.

“We know the risks we are returning to,” he said. “There’s nothing good about going back. But there’s no way I’m taking the risk of keeping my family here any longer.”