MATAMOROS, Mexico (AP) — About two dozen makeshift tents were set ablaze and destroyed at a migrant camp across the border from Texas this week, witnesses said Friday, a sign of the extreme risk that comes with being stuck in Mexico as the Biden administration increasingly relies on that country to host people fleeing poverty and violence.

The fires were set Wednesday and Thursday at the sprawling camp of about 2,000 people, most of them from Venezuela, Haiti and Mexico, in Matamoros, a city near Brownsville, Texas. An advocate for migrants said they had been doused with gasoline.

“The people fled as their tents were burned,” said Gladys Cañas, who runs the group Ayudandoles A Triunfar. “What they’re saying as part of their testimony is that they were told to leave from there.”

There were no reports of deaths or significant injuries. But about 25 rudimentary shelters made up of plastic, tarps, branches and other materials were torched in a sparsely populated part of the camp. Many who lived there also apparently lost clothing, documents and whatever other modest belongings may have been left inside.

Margarita, a Mexican woman staying at the camp, said Friday she saw migrants from Venezuela screaming during the previous day’s blaze.

“They had their children with them and a few other things they had a chance to get,” Margarita said. She spoke on the condition that her last name not be published due to fears for her safety.

Gangs recently threatened migrants who were wading across the river border illegally, as well as their guides, Margarita said, but the crossings had continued.

Criminal groups often prey upon migrants in the area and demand money in return for permission to pass through their territory.

However, Juan José Rodríguez, director of the Tamaulipas Institute for Migrants, a state agency coordinating with Mexico’s federal government, said he had no information that a gang was responsible for the fires.

Rodríguez attributed them to a group of migrants and said some 10 tents that had already been abandoned were burned. He added that they apparently set the fires to express frustration with a U.S. government mobile app that assigns turns for people to show up at the border and claim asylum.

Migrants have been applying for 740 slots made available daily on the glitch-plagued app, CBPOne, which allows them to enter the U.S. legally at an official crossing.

There are far more migrants than available slots, exacerbating tensions in Mexican border cities that house them, often in shelters and camps like the one in Matamoros. Last year hundreds of migrants blocked a major pedestrian crossing between Tijuana and San Diego until authorities shut down the protest.

In Matamoros on Wednesday night, about 200 migrants gathered on the southern side of an international bridge and halted all US-bound traffic, the U.S. Customs and Border Protection reported. Vehicles were able to resume crossing after about two hours and pedestrians were allowed to cross after about four hours.

CBP made no mention of fires at the Mexican camp in its statement about the bridge shutdown.

The tent fires in Matamoros come on the heels of a March 27 blaze that killed 40 men at a Mexican immigration detention center in Ciudad Juarez. The fire was allegedly started by a detained migrant to protest conditions at the facility in the city across from El Paso, Texas.

The US government is increasingly turning to Mexico while preparing to end pandemic-era asylum restrictions, known as Title 42 authority, on May 11. Mexico recently began accepting people from Cuba, Haiti, Nicaragua and Venezuela who cross the border irregularly and are turned back by the U.S.

The Biden administration also is putting final touches on a policy under which asylum would be denied to people who pass through another country, such as Mexico, to reach US soil.