By Daina Beth Solomon

CIUDAD ACUNA, Mexico (Reuters) – U.S. President Joe Biden faced pressure on Tuesday to halt the expulsion of asylum seekers to Haiti from a Texas border camp, as worries about their safety compounded disquiet at images of officials on horseback using reins as whips against migrants.

Several hundred have been sent to Haiti from the camp in Del Rio, Texas, since Sunday. Thousands more have been moved into U.S. detention for processing and more flights are due to leave on Tuesday, Department of Homeland Security Secretary Alejandro Mayorkas said.

U.S. Senate Majority Leader Chuck Schumer urged fellow Democrat Biden to put an immediate end to the expulsions, adding to similar calls from several United Nations agencies.

Schumer said sending Haitians back to their home country, where a presidential assassination, rising gang violence and a major earthquake have spread chaos in recent weeks, “defies common sense.”

“It also defies common decency,” he said, calling images taken in recent days of mounted U.S. border agents using horse reins like whips “completely unacceptable.”

“The images turn your stomach. It must be stopped.”

The sprawling camp containing up to 10,000 mostly Haitian migrants under a bridge spanning the Rio Grande is a new flashpoint for the White House, already grappling with record numbers of border arrivals that Republican Senator Mitt Romney on Tuesday called a “disaster.”

The camp’s population peaked at up to 14,000 at the weekend, but has since diminished.

Mexican authorities also appeared to be detaining some of the migrants, who have regularly crossed back over to Mexico to get food.

A Reuters crew witnessed migrants who appeared to be Haitian detained on the streets of Ciudad Acuna across the river from the main camp on Monday by agents flanked by Mexico’s National Guard.

In one encounter, several migrants yelled and protested as agents boarded them into a National Immigration Institute (INM) van. INM did not immediately respond to a requests for comment.

The clashes at the border were also criticized by Mayorkas, who pushed ahead on Tuesday with moving migrants out of the camp to be flown to Haiti.

Speaking to CNN, Mayorkas said 4,000 Haitians had been moved from the camp. It was not clear if all of those were to be expelled from the United States, although he announced four flights were expected on Tuesday.

HOPE

Despite the risk of being returned to Haiti after sometimes years-long journeys through Latin America to reach the United States, the hope of being let in meant many migrants remain in the camp.

Carly Pierre, 40, said he was staying in the U.S. camp because he saw a chance to make it into the country with his wife and two children, ages 3 and 5, after several years living in Brazil.

“There are deportees, and there are people who will make it in,” he said, shorts still wet from having crossed the river to buy ice and soda at a convenience store on the Mexican side.

Despite the outcry over mistreatment and anger in Del Rio about the camp, Mayorkas emphasized that U.S. border agents were delivering medical attention and were working with the Red Cross.

In Ciudad Acuna, residents were also bringing relief to the migrants, after a couple of hundred gathered in a shady area resting on pieces of cardboard and blankets.

Jessica de la Garza, 22, who helped organize a drive on Facebook to collect donations, early on Tuesday distributed coffee, water, milk, sandwiches, cereal, beans and diapers.

“They say, ‘Thank you Mexico,’ because we are helping a little. The need is great, and so is the empathy.”

(Reporting by Daina Beth Solomon in Ciudad Acuna, Additional reporting by Doina Chiacu in Washington; Editing by Bernadette Baum and Rosalba O’Brien)