US warns of extremism after Texas synagogue attack, bomb threats in colleges

The United States faces heightened threats from extremist groups domestic and foreign, underscored by last month's hostage standoff crisis in a Texas synagogue and bomb threats at many historically Black colleges and universities, a US government agency said on Monday.

The warning comes after some schools across the United States cancelled classes and issued shelter-in-place orders last week. Investigators ultimately failed to turn up any explosives.

"Threats directed at Historically Black Colleges and Universities (HBCUs) and other colleges and universities, Jewish facilities, and churches cause concern and may inspire extremist threat actors to mobilize to violence;" the Homeland Security Department said in a bulletin.

Last month, British-born gunman Malik Faisal Akram took four people hostage at Congregation Beth Israel in Colleyville, Texas, including its rabbi, Charlie Cytron-Walker. He brandished a gun and held them hostage for 10 hours. The standoff ended in gunfire, with all four hostages released unharmed and the suspect dead.

The agency also warned that Daesh or its affiliates may issue public calls for retaliation due to a US special forces raid in Syria last week that led to the death of the group's leader, Abu Ibrahim al-Hashimi Al Quraishi.