The Department of Homeland Security has launched an investigation after a disturbing video of border patrol agents’ treatment of Haitian migrants at the U.S.-Mexico border surfaced on social media. In some images, the agents, who were on horseback, appeared to be whipping the migrants who are seeking asylum in the U.S.

On Monday (Sept. 20), the department said it would investigate the situation to “define the appropriate disciplinary actions [that need] to be taken.”

“U.S. Customs and Border Protection’s Office of Professional Responsibility is investigating the matter and has alerted the DHS Office of Inspector General,” a DHS spokesperson said. The department has also dispatched additional agents to oversee what’s going on at the Del Rio, Texas border.

After footage from the border went viral, House Speaker Nancy Pelosi and several other politicians spoke out against agents’ treatment of the migrants.

“Reports of the mistreatment of Haitian migrants fleeing violence and devastation from natural disasters are deeply troubling, including the inappropriate use of what appear to be whips by Border Patrol officers on horseback to intimidate migrants,” she tweeted.

Congress is “closely monitor[ing] developments” at the scene, she added.

A DHS official further called footage of agents confronting migrants “extremely troubling.”

“I don’t think anyone seeing that footage would think it’s acceptable or appropriate,” White House press secretary Jen Psaki said at a briefing earlier on Monday.

As reported by REVOLT, thousands of Haitians fleeing damage from the country’s catastrophic earthquake and political violence in the wake of the assassination of Former President Jovenel Moïse created makeshift camps at the border hoping to gain entry into the U.S. According to NBC; almost 3,300 people have already been turned away from Del Rio since Friday (Sept. 17). At one point; more than 12,000 migrants were camping at the border.

“We have no choice at this point but to increase repatriation flights,” U.S. Department of Homeland Security head Alejandro Mayorkas said. The first of three flights returned 327 people to Haiti on Sunday (Sept. 19) while other migrants could be transported to “other countries,” he added.