"During this attack, an Alvarado Police Officer was shot and wounded," according to the FBI notice. "On July 9, a federal arrest warrant was issued for Song in the United States District Court, Northern District of Texas,

Officials have brought charges against a twelfth suspect in the attack on a Fort Worth-area ICE facility.

The attack by the far-left activists comes as federal authorities warn that ICE officers are facing a dramatic increase in threats and assaults.

The Blue Alert system, launched in 2008, is designed to help locate suspects who have seriously injured or killed law enforcement officers.