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

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.

One police officer was wounded after at least two people shot at officers outside an immigration detention center in Texas, according to a criminal complaint in federal court.