One person has died and another been injured at a shooting at a US university, officials say.

Winston-Salem State University says a suspected gunman is on the loose and visitors to the campus are urged to be cautious and stay away from restricted areas.

The shooting was reported around 1:20 am on Sunday near Wilson Hall and Gleason-Hairston Terrace. The campus was quickly placed on lockdown and movement restricted for about three hours until around 4:50 am.

The university says both of the victims are believed to be students. The suspect is not believed to be a current student.

The historically black school in Winston-Salem was celebrating its homecoming weekend, when former students and staff return.

Campus police could not be reached for comment.