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.

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.

Alvarado police offers were dispatched to the detention center in the 1200 block of Sunflower Lane around 10:56 p.m. Friday, according to the Johnson County sheriff’s office. The call was made to investigate a report of “a suspicious person.”