The Trump administration has closed an outdoor holding pen under an El Paso international bridge that held hundreds and possibly thousands of migrants in conditions the American Civil Liberties Union called “an extreme and unprecedented assault on their basic human rights.” Migrants detained under the bridge have begun telling stories of horrific conditions, including children bruised by sleeping on rocky ground for days and illnesses going untreated.

“They treated us like we are animals. They call us bodies,” said Carlos, a 31-year-old Honduran man who spent three and a half days being held under the bridge with his wife and two children before being moved to a Border Patrol detention facility in Lordsburg, New Mexico, on Thursday. He showed bruises on his 6-year-old son’s legs that he said were caused by sleeping on rocks, and a rash on his 5-year-old daughter’s hands that went untreated while they were detained under the bridge. Carlos said he saw pregnant women who appeared to be near full term sleeping on the ground. Parents gave their coats and thin Mylar blankets to their children to try to give them some warmth as they slept outside. Carlos said he slept about three hours total during his time under the bridge.

The controversy over the El Paso bridge facility was part of a dizzying array of immigration and border developments over the weekend. President Trump again threatened to close the border because he felt Mexico wasn’t doing enough to block Central American migrants from coming to the United States. Trump also announced he was cutting off foreign aid to Guatemala, Honduras, and El Salvador because he thought those countries weren’t doing enough to keep their people from leaving. House Judiciary Committee chairman Jerrold Nadler, D–New York, called the cutoff of foreign aid “stupid” during a visit to El Paso on Sunday. He said ending aid will increase immigration to the United States from the Northern Triangle countries.

“I felt what they were trying to do was to hurt us psychologically, so we would understand that this is a lesson we were being taught, that we shouldn’t have crossed,” Carlos said in an interview with Texas Monthly on Sunday at an El Paso shelter where he and his family are staying temporarily. “We felt that what they were teaching us is as Latino immigrants that we should let our families know that there was this big risk [in coming to the United States]. But regardless, it was worth it, because even though we had to go through this big risk with our children, we’re in better conditions now.”

U.S. Customs and Border Protection began holding people in a tent under the bridge in early March and took media near the site on Wednesday following an El Paso news conference by CBP commissioner Kevin McAleenan. CBP said in a statement Sunday that the migrants who had been held under the bridge had been moved to the main Border Patrol station in El Paso, with an area adjacent to the bridge being used as a processing facility for migrants. “The number of apprehensions has continued to increase steadily and the decision was made to relocate to a location with more space and more shelter capability,” the statement said. A group of migrants could be seen Sunday afternoon in a new tent just east of the bridge, but the numbers appeared to be far smaller than last week.

CBP officials declined to respond to emerging stories of abuse of migrants being held under the bridge. The ACLU filed a five-page complaint late Saturday with Department of Homeland Security officials alleging that migrants were forced to sleep outside on the ground in temperatures as low as 37 degrees with only a thin Mylar sheet for warmth. The complaint also alleged that Border Patrol agents used sleep deprivation practices, verbally and physically abused migrants, refused medical care even to sick children, and provided inadequate food and water.

ACLU staff interviewed a person who said “Border Patrol agents threw out the medication she carried for her four-month-old child and did not provide her with any treatment for her child’s fever. Migrants reported developing fever, nausea, and coughing while being held in this outside area. Yet, these migrants, including infants and children, are also denied medical treatment by Border Patrol agents,” said the complaint, filed by the ACLU of Texas and its Border Rights Center in El Paso. One agent allegedly told a pregnant woman in Spanish, Why didn’t you have your [expletive] child in your own country? It costs me $25,000 a year to support your [expletive] child,” the complaint said.

Detaining migrant families outdoors, where they face severe exposure to the elements and lack adequate basic care, is an extreme and unprecedented assault on their basic human rights and a failure of CBP to meet its basic duties as a government agency. This practice must stop immediately, and the Office of Inspector General should conduct an investigation to ensure that such unconscionable acts are never authorized again,” the ACLU said in the complaint.

The migrants were moved hours before a congressional delegation led by Nadler was scheduled to visit the facility. The delegation wound up touring the El Paso Border Patrol station where hundreds of migrants are now being held after officials moved people from under the bridge. “What we saw was a detention facility that was grossly, grossly overcrowded with people. We saw people lying in a room, one room with women, one with men. No place to sit down, no chairs, no beds, nothing,” Nadler said. “It’s apparent to me that the personnel there are doing the best they can but it is grossly overcrowded.”

CBP did not respond to questions about how many migrants were held under the bridge. Over the past week, several hundred people were visible to pedestrians walking across the bridge that connects downtown El Paso to Ciudad Juárez, Mexico. Numerous Democratic leaders roundly criticized holding migrant families under the bridge, including presidential candidate Beto O’Rourke, who officially kicked off his campaign in his hometown Saturday with a rally less than a mile from the Paso del Norte Bridge.

Although the number of border apprehensions is below the levels of the late nineties and early aughts, recent months have seen record levels of families crossing the border, mostly from the Central American countries of Guatemala, Honduras, and El Salvador. The families walk across the border, often in areas with extensive fences and walls, surrender to Border Patrol agents, and request asylum. Unlike Mexican migrants who cross the border illegally, Central American families seeking asylum can’t be quickly deported. That has led to families being detained in cramped facilities that CBP has acknowledged were never intended to house them.

CBP commissioner McAleenan said in the news conference in El Paso on Wednesday that border agents expect to take 100,000 migrants into custody in March, the highest monthly total since 2008. McAleenan and Homeland Security Secretary Kirstjen Nielsen have said the increasing flow of families has overwhelmed the nation’s border security network, a claim the ACLU rejected in its complaint. The number of Border Patrol agents grew from 9,212 agents in 2000 to 19,555 in 2018. CBP’s budget has also more than doubled since 2006, growing from $7.1 billion in 2006 to $16.69 billion this year. It is inconceivable that the agency does not have the resources, if appropriately allocated, to ensure humane treatment of migrants in their custody,” the complaint said.

CBP has said it held migrants under the bridge for less than 24 hours while awaiting a move to other Border Patrol detention facilities where they could be processed. But groups working with migrants have said stays of four to five days were common. Carlos, the Honduran man interviewed by Texas Monthly, said some agents used threats of a continued stay under the bridge as a way of bending migrants to their will. “The bad ones would say, if you keep acting like animals, if you keep acting so disorganized, you’re going to be here a few more days as punishment.

NOTE: This post has been updated to correct the spelling of Kirstjen Nielsen’s first name.