PAUL RATJE via Getty Images "Viper" and "Stinger" — armed members of the Constitutional Patriots New Mexico Border Ops Team militia — patrol the border last month in Sunland Park, New Mexico.

New Mexico’s governor has ordered a right-wing militia to stand down and stop illegally holding migrants — often at gunpoint ― in her state.

“Regular citizens have no authority to arrest or detain anyone,” Michelle Lujan Grisham said Friday.

“That migrant families might be menaced or threatened in any way, shape or form when they arrive at our border — often times after an unimaginably arduous journey — is completely unacceptable,” Lujan Grisham said in an email to NBC News.

The American Civil Liberties Union alerted the governor to the militia in a letter Thursday. The vigilantes, who call themselves the United Constitutional Patriots, “arrested” nearly 300 people near Sunland Park in New Mexico on Tuesday, according to the letter.

A video revealing the “operation” has been posted online by the group (below). A woman with the militia can be heard telling others not to point guns at the migrants while they wait for U.S. Border Patrol agents to arrive to collect the asylum seekers.

The ACLU characterized the group as an “armed fascist militia organization” made up of “vigilantes” working to “kidnap and detain people seeking asylum.”