Three detainees were shot at an Immigration and Customs Enforcement facility in Dallas this morning, the Department of Homeland Security said in a statement, writes NBC NEWS.

One person is dead, and two others are in critical condition, according to DHS. No ICE officers were hurt, Dallas police said at a news conference. The victims’ identities have not been publicly released.

The shooter, who was found dead with a self-inflicted gun wound, has been identified as Joshua Jahn, according to multiple senior law enforcement officials briefed on the investigation.

A bullet found near the shooter bore messages that were “anti-ICE in nature”, special agent in charge of the Dallas FBI office, Joe Rothrock, said at a news conference. He said the attack was an act of “targeted violence”. The shooter fired multiple rounds from a nearby roof or an elevated position down into the field office’s sally port, an ICE spokesperson confirmed.

The motive or what the shooter was targeting was not immediately clear.