The American Civil Liberties Union is warning that armed vigilantes are working directly with the U.S. Border Patrol to unlawfully detain hundreds of migrants at gunpoint along the U.S.-Mexico border. The ACLU cites videos posted on social media showing members of a militia group pursuing migrants in New Mexico’s desert west of El Paso, Texas, and effectively kidnapping them against their will. In one video, vigilantes armed with assault rifles are seen approaching a group of several dozen people seated on the ground, as the video’s narrator, a man named Jim Benvie, films.

Jim Benvie: “Hey, guys. This is Jim with the United Constitutional Patriots and We Build the Wall. … As you can see, we did actually end up getting everybody wound up. It was a combination of us and some good horses over there and basically a team effort here.”

In a letter to New Mexico’s governor and attorney general calling for an investigation, the ACLU called the United Constitutional Patriots an “armed fascist militia organization,” adding, “The Trump administration’s vile racism has emboldened white nationalists and fascists to flagrantly violate the law.”