For the second time this month, at least six historically Black colleges and universities (HBCUs) have received bomb threats.

On Monday (Jan. 31), Bowie State University, Howard University, Southern University, Bethune-Cookman University, Albany State University and Delaware State University all reported possible threats. Judson Bible College, which is not an HBCU, was also targeted. Five of those schools remain either on lockdown or have issued shelter-in-place orders for their faculty and students.

According to ABC News, the U.S. Federal Bureau of Investigation (FBI) knows about the series of bomb threats and is working with law enforcement to manage them. “As always, we would like to remind members of the public that if they observe anything suspicious to report it to law enforcement immediately,” the FBI said in a statement to the outlet.

Thomas Chittum, the acting deputy director of the Bureau of Alcohol, Tobacco, Firearms & Explosives, also said that their agents are reacting to the warnings. “We can confirm that ATF has responded,” Chittum told journalists on a call Monday. “Of course, it is a federal crime to use interstate facilities to make a bomb threat, and so ATF will provide our investigative expertise and support to that investigation, but obviously, the facts are preliminary and unfolding.”

A Washington Metropolitan Police Department spokesperson told CNN that there were “no hazardous materials found” at Howard University.

As REVOLT previously reported, earlier this month, students and employees from at least seven HBCUs — the University of Arkansas at Pine Bluff, Florida Memorial University, Howard University, Norfolk State University, North Carolina Central University, Prairie View A&M University and Xavier University — were forced to evacuate their campus after bomb threats were made.

After initial probes, no active devices or explosions were found. All-clear notices were sent out the next morning, and students who briefly left campus returned to their dormitories.