WOODSTOCK, Ga. — At least a half-dozen historically Black universities in five states and the District of Columbia were responding to bomb threats Monday, with many of them locking down their campuses for a time.

Both the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are investigating, the agencies said in separate statements.

In Georgia, Albany State University warned students and faculty on social media that “a bomb threat has been issued to Albany State University’s academic buildings.”

School officials at Southern University and A&M College in Baton Rouge, Louisiana, told students to stay in their dormitories Monday morning. After a search for any suspicious devices, the university gave an all-clear later in the day. Normal campus operations were expected to resume Tuesday, school officials said.

At Bowie State University in Maryland, school officials told everyone on campus to shelter in place until more information was available. Explosives-detecting dogs and bomb technicians were helping campus police to sweep buildings, the state fire marshal’s office said in a statement. The campus reopened later Monday after a search by local, state and federal law officers found no explosive devices, school officials said.

Howard University was also the subject of a bomb threat before dawn Monday, but later gave an all-clear to students and staff, radio station WTOP reported.

In Florida, Daytona Beach police said in a tweet that they gave the all-clear at the Bethune-Cookman campus after the school received a bomb threat. But classes were canceled and police said they were going to stay on campus for the rest of the day.

Delaware State University spokesperson Carlos Holmes told news outlets that a bomb threat to that campus was made early Monday morning.

White House Press Secretary Jen Psaki said Monday that the threats “are certainly disturbing and the White House is in touch with the interagency partners, including federal law enforcement leadership on this.”

“We’re relieved to hear that Howard and Bethune-Cookman universities have been given the all-clear and will continue to monitor these reports,” Psaki said, adding that President Joe Biden is aware of the threats.

Monday’s bomb scares came one day before the start of Black History Month and less than a month after a series of bomb threats were made to multiple historically Black universities on Jan. 4.

“We are deeply disturbed by a second round of bomb threats at HBCU campuses within a month,” leaders of the Congressional Bipartisan HBCU Caucus said in a statement Monday.

“Learning is one of the most noble and most human pursuits, and schools are sacred places that should always be free from terror,” it said. “Solving these crimes and bringing those responsible to justice should be a top priority for federal law enforcement.”

The statement was issued by Democratic U.S. Rep. Alma Adams of North Carolina and Republican U.S. Rep. French Hill of Arkansas, who are co-chairs of the caucus.

Associated Press writer Sarah Brumfield in Silver Spring, Maryland, contributed to this report.