Multiple Historically Black Colleges and Universities, or HBCUs, say they received serious threats on Thursday, a day after right-wing influencer Charlie Kirk was shot dead on a college campus in Utah.

The schools that received threats, in addition to some HBCU campuses acting out of an abundance of caution, have ceased campus activity in some way.

Alabama State University, located in Montgomery, said it had received “a terroristic threat” directed at the campus and had shut down facilities for the remainder of the day, including classes, rehearsals and any other scheduled events. The school has police clearing all buildings on campus.

Hampton, Virginia’s Hampton University also announced it had “received notice of a potential threat” and canceled all campus activities for both Thursday and Friday. The university encouraged all students who live on campus to “minimize their movement” in the area and asked that everyone remain “vigilant” and report any suspicious activity.

Virginia State University, located in Ettrick, said it’s gone into lockdown “out of an abundance of caution” after receiving a threat, too.

After Clark Atlanta University received a threat, multiple Atlanta-area HBCUs also enacted lockdowns, including Morris Brown, Morehouse and Spelman colleges, The Atlanta Journal-Constitution reported.

Bethune-Cookman University in Daytona Beach, Florida, and Southern University in Baton Rouge, Louisiana, have also announced threats.

Rep. Jasmine Crockett (D-Texas) said her “heart aches for the constant trauma” students face with the threat of gun violence.

“HBCU campuses have been safehavens since their creation,” she posted on social media. “I’m not sure why or how they have become a target today, but it is not ok.”

Rep. Troy Carter (D-La.) called for the federal government to “utilize every available resource to identify, apprehend, and prosecute those responsible” for the threats, saying they cannot be minimized.

“HBCUs are pillars of excellence, resilience, and progress,” he said in a statement. “They have nurtured leaders, broken down barriers, and carried forward the torch of justice and equality in America. Any threat against them is a threat against us all.”

The threats come a day after Kirk was shot and killed while speaking during a campus event at Utah Valley University in Orem, Utah.