Police at the University of North Carolina at Chapel Hill are responding to an “armed and dangerous person on or near campus,” according to an alert from the university on Monday.

A spokesperson for the university declined to comment further on the incident. Calls to the Town of Chapel Hill were not immediately returned.

A witness on campus told CNN they are currently locked down in their building and see armed officers searching campus.

University police advised all students to go inside immediately, close windows and doors and to wait until further notice, according to an email.