A federal law enforcement source told CBS News that local police arrested eight people. The official said some of those apprehended were wearing body armor.

A Blue Alert was issued on Wednesday for a man accused of shooting an Alvarado police officer during an attack at a U.S. Immigration and Customs Enforcement detention facility on July 4, according to the Texas Department of Public Safety and the FBI.

Eleven people are facing charges over a “planned ambush” that led to an officer being shot outside an Immigration and Customs Enforcement detention facility in Alvarado, Texas, last week, federal officials announced Monday.