NUEVO LAREDO, Mexico — When the United States began sending asylum seekers to wait in Mexico earlier this year as their claims were processed, many regarded the dangerous northeastern state of Tamaulipas as a worst-case scenario.
The State Department warned against all travel to Tamaulipas — the same risk level it issues for Syria and Afghanistan. Doctors Without Borders found that 45 percent of its patients in this city, among the largest in the state, ‘‘suffered at least one episode of violence in the city, as they waited to cross into the US.’’
But on Tuesday morning, the United States sent the first 12 migrants back to Tamaulipas under a program known as the Migration Protection Protocols. Mexican authorities dismissed them from the city’s immigration office without any transportation or assistance.
‘‘Where do we go?’’ asked José Luis Romero, 31, who had fled Venezuela with his wife and two sons, ages 6 and 8. There was no response from Mexican authorities, who remained inside the office.
Romero and his family had waited in Nuevo Laredo for three months until, on Monday morning, US officials had called for them.
Romero was separated from his wife and children by immigration officials after they were taken across the border to Laredo, Texas. They were interviewed separately. They each explained how they had protested against Venezuelan President Nicolás Maduro in the city of Maracaibo, how security forces had later raided their home.
On Tuesday — without warning, after their interviews — they were sent back across the border together, their next court date scheduled for Sept. 24.
‘‘We had given away our mattresses. No one told us they would send us back here to wait,’’ he said.
Romero and his family dragged their luggage through the streets for a few blocks. It was 97 degrees at 11 a.m. For months he had tried to keep a low profile here, after hearing of other migrants being kidnapped. Now he was left to wander around. The others in the group — all Cubans — had split off and were walking in a different direction.
‘‘I was told not to talk to anyone because of my accent, not to leave the shelter because we are targets,’’ Romero said.
For months, the city’s shelters had been overflowing. Some migrants who left to work or buy food were seized by armed groups. Aaron Mendez Ruiz, who runs a migrant shelter called ‘‘Amar,’’ said 15 migrants from the shelter have been kidnapped this year. One was a Cuban man, Carlos Cordero Roque, 31, who was released by his captors on Sunday night, with bruises lining his back.
Recently, the armed men have been demanding payments of $5,000 from migrants, assuming their relatives in the United States will pay. Roque was held for two weeks before the money arrived, he said.
‘‘There’s no question that they specifically go after the migrants,’’ Ruiz said.
Eventually on Tuesday, Romero called the manager of a different migrant shelter who sent a white truck to pick up the family from a street corner in Nuevo Laredo. Twenty minutes later, Romero got in the front seat. His wife and kids jumped in the bed of the truck.
The Trump administration intended the Migrant Protection Protocols program to be a way of reducing the number of migrants who live and work in the United States while they wait for their asylum hearings. The backlog in US asylum courts means many migrants wait years for a hearing.
By June, 11,000 migrants had been sent to Mexico to await their asylum hearings, mostly in Tijuana and Ciudad Juarez. But the US-Mexico migration deal last month has allowed for the rapid expansion of the program.
Mexican officials said they expected tens of thousands of asylum seekers to be returned under the program over the next several months. There was no way to carry out that expansion, officials said, without launching the program in Tamaulipas.
For years, migrants have been targeted in the state. In 2010, 72 migrants were killed in rural San Fernando. Police found their decomposing bodies and later accused the Los Zetas criminal syndicate of the killings.
The state’s officials were outraged that Tamaulipas was being considered as a destination for asylum seekers to wait out their cases.
Tamaulipas ‘‘will not be a crossing point for returned asylum seekers,’’ said the governor, Francisco Javier García Cabeza de Vaca in a statement on Monday.
‘‘Our shelters are already overwhelmed,’’ said Raul Cardenas, the city manager of Nuevo Laredo, in an interview. ‘‘We don’t have the resources to handle this in our city.’’
Cabeza de Vaca and officials in Nuevo Laredo threatened to expel the migrants to a different state, further from the border. They complained that Mexico’s federal government had signed a deal with the Trump administration without consulting or assisting the border states that would need to provide for asylum seekers.
The Department of Homeland Security gives returnees a list of lawyers in South Texas, but many say they are not willing to meet with clients in Nuevo Laredo because of security concerns.
‘‘I don’t know any pro-bono immigration lawyers who are ready to tend to this group,’’ said Nelly Vielma, an immigration attorney who is also a Laredo city councilwoman. ‘‘Right now, we are trying to figure out if we can handle some of the cases over Skype.’’