Students and employees from at least seven historically Black colleges and universities were forced to evacuate their campuses following bomb threats.

Between Tuesday afternoon and night (Jan. 4), officials at 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 of Louisiana alerted authorities of bomb threats at their respective schools and ordered evacuations or lockdowns to keep their campus communities safe.

“Prairie View A and M University has received a bomb threat,” the Texas school tweeted. “Please remain where you are.”

NCCU sent an email ordering members of campus to “proceed immediately to the nearest exit and vacate the building.” “This is not a drill,” the school wrote in all caps, per The News & Observer.

After initial investigations, no active devices or explosions were reported. All-clear notices were sent out on Wednesday morning (Jan. 5), and students who briefly relocated off-campus returned to their residence halls.

“Although the threat was unfounded we ask that everyone remains vigilant,” the University of Arkansas at Pine Bluff tweeted. Howard University and Norfolk State added that their campuses were secured. Officials at Xavier University said they will remain on high alert and will increase security to ensure the safety of students and faculty.

It is not clear whether the HBCU bomb threats were connected or racially motivated.

As the Washington Post reported, the threats come nearly two months after Cornell University, Columbia University and Brown University — three Ivy League schools — issued emergency alerts and evacuation orders after receiving similar bomb threats. Normal activities resumed after law enforcement officials determined that the threats were not credible. Yale University also reported bomb threats on multiple buildings back in November; officials sent out an all-clear notification five hours later.