CHAPEL HILL, N.C. -- The University of North Carolina at Chapel Hill sent out an alert Monday warning of an “armed, dangerous person on or near campus” and urging people to go inside and avoid windows.

The first alert was sent out just after 1 p.m. At 1:50 p.m., officials posted on X, formerly known as Twitter, that the shelter-in-place order remained in effect and that it was “an ongoing situation.” About 40 minutes later, the school added a post saying: “Remain sheltered in place. This is an ongoing situation. Suspect at large.”

Officials said as soon as they had verified information, they would share it.

Video footage showed a heavy police presence on the campus of the state's flagship university, where the fall semester started last week.

Campus officials did not immediately respond to an email seeking additional information.

Nearby Chapel Hill-Carrboro City Schools posted on social media that all doors would be locked at its schools and offices until authorities say it's safe.

Associated Press writers Sarah Brumfield in Silver Spring, Maryland, and Sarah Rankin in Richmond, Virginia, contributed to this report.