ALVARADO, Texas (AP) — Ten people have been arrested on attempted murder charges in connection with a shooting outside of a Texas immigration detention center that wounded a police officer, where people in black military-style clothing fired at authorities in a “planned ambush,” a U.S. attorney said.

A U.S. attorney called the wounding of a police officer an ‘ambush’ and warned of increasing violence against immigration agents.

Ten people have been charged with attempted murder of federal agents over the shooting outside the Prairieland Detention Centre in Alvarado, Texas, on Friday