Bomb threats forced several historically Black universities into lockdown Tuesday morning for a second consecutive day.

CNN reported that Coppin State University, Mississippi Valley State University, Morgan State University, Alcorn State University, Tougaloo College, Jackson State University, Kentucky State University, Fort Valley State University, Howard University, Xavier University, University of the District of Columbia, Spelman College and Edward Waters University all received threats Tuesday.

A Medgar Evers College spokesperson told News 12, "We have not received any threats nor has any CUNY school. We have increased security on campus."

On Monday, at least a half-dozen historically Black universities in five states and the District of Columbia received bomb threats, with many of them locking down their campuses for a time.

In warnings to students, school officials say some of the threats were directed at academic buildings.

The FBI said on Monday that it “is aware of bomb threats received by some Historically Black Colleges and Universities," the agency said in a statement provided by Jenna Sellitto, an FBI spokesperson in Atlanta. “The FBI takes all potential threats seriously, and we regularly work with our law enforcement partners to determine their credibility."

The Bureau of Alcohol, Tobacco, Firearms and Explosives also responded to the threats and was working with local law enforcement to continue investigating, acting Deputy Director Thomas Chittum said.