DURHAM, N.C. (WNCN) — Authorities blocked off the North Carolina Central University campus Tuesday evening amid a lockdown and evacuation triggered by a bomb threat, university police said.

A news release from N.C. Central officials said, “The campus is on lockdown as it is an active police investigation.”

N.C. Central police later told CBS 17 that a bomb threat around 5:30 p.m. led to the lockdown.

N.C. Central was one of at least seven Historically Black Colleges and Universities that received bomb threats Tuesday, school officials said in a news release.

The all-clear was issued at 9:15 p.m. Students who were temporarily off-campus were taken back to their residence halls, a university news release said.

Norfolk State University was evacuated after a bomb threat Tuesday evening, WAVY-TV reported. Howard University also reported a potential bomb threat on campus Tuesday afternoon.

Xavier University in New Orleans received a bomb threat Tuesday, according to WDSU-TV. The Senior Student Class Council of Prairie View A&M University in Texas reported the school also received a bomb threat.

Earlier Tuesday evening, several Durham city police cars were near the campus and one N.C. Central police vehicle was blocking an entrance to the campus.