DEL RIO 一 U.S. Department of Homeland Security Secretary Alejandro Mayorkas on Monday sent a message to migrants, particularly Haitians, attempting to enter the country through the southwest border: “People coming to the United States illegally will be returned, your journey will not succeed.”

Mayorkas’ comments in Del Rio come as lawmakers and immigrants rights advocates denounced the treatment of some Haitians by Border Patrol agents. Images and videos taken by journalists and widely shared on social media show agents on horseback charging and herding migrants attempting to cross the Rio Grande, including an agent swinging his reins toward a migrant.

On Monday, Mayorkas denied that agents whipped anyone but said officials would “investigate the facts.” White House press secretary Jen Psaki denounced the agent’s actions at a news conference in Washington, D.C., on Monday: “I don’t think anyone seeing that footage would think it was acceptable or appropriate,” she said.

U.S. Rep. Veronica Escobar (D-El Paso) called the agent’s behavior “unacceptable” in a tweet. “No matter how challenging the situation in Del Rio is right now, nothing justifies violence against migrants attempting to seek asylum in our country,” she tweeted.

The Refugee and Immigrant Center for Education and Legal Services, a Texas immigrant rights organization, compared the agents’ behavior to the Ku Klux Klan during the post-Civil War era.

“The dehumanizing and abusive treatment by the government through the use of legislative and police powers is not new to Black people in America,” Nicole Morgan, an attorney with RAICES, said in a statement.

The controversy comes as the federal government has sent reinforcements to Del Rio to deal with as many as 15,000 migrants camped under the international bridge connecting the city with Mexico, hoping to request asylum in the U.S.

Mayorkas said 3,500 migrants have been moved from Del Rio to other processing centers and the goal was to move another 3,000.

With little food, water, or hygiene products, some of the migrants have passed out from dehydration and at least five have given birth in Del Rio hospitals, Val Verde County Judge Lewis Owens has said.

Repatriation flights to Haiti and other countries of origin started on Sunday. Mayorkas said the goal is to have one to three flights a day.

He said most of the migrants are being expelled under Title 42, the pandemic health order issued by the U.S. Centers for Disease Control and Prevention last year to rapidly expel migrants to Mexico or their home countries without the opportunity to ask for asylum. A federal judge last week blocked the Biden administration from using Title 42 to expel migrant families but stayed the order for 14 days. The Biden administration appealed that ruling Friday.

Haiti was hit by a 7.2-magnitude earthquake in August, a month after its president was assassinated — the latest tragedies for a country battered by political instability and turmoil.

“We are very concerned that Haitians who are taking this irregular migration path are receiving false information that the border is open or the temporary protected status is available,” Mayorkas said. “I want to make sure that it is known that this is not the way to come to the United States.”

Some Haitians decided to flee their country after the president’s assassination, starting in South American countries such as Bolivia or Chile. Some of them are attempting to reconnect with families who emigrated to the United States.

Many of the migrants say they decided to enter through Del Rio because the route was safer than other parts of Mexico. Others said they were following the crowd.

Gov. Greg Abbott on Monday sent a letter to President Joe Biden requesting that the federal government issue an emergency declaration for Texas because of the growing number of migrants under the Del Rio bridge.

“This surge poses life-threatening risks to residents of Val Verde County and is quickly overrunning law enforcement and health care and humanitarian resources which were never intended to be used in this capacity,” Abbott said in a statement. “Even the limited federal resources in the area are strained by the large number of individuals illegally crossing into Texas.”

Abbott also announced $100 million in state grants for municipal governments along the border to beef up law enforcement operations and help cover the costs of detaining and prosecuting migrants and handling bodies of migrants found along the border.

This article originally appeared in The Texas Tribune, a nonpartisan, nonprofit media organization that informs Texans — and engages with them — about public policy, politics, government, and statewide issues.

Uriel J. García, The Texas Tribune

Uriel J. García is an immigration reporter for The Texas Tribune based in El Paso.