Virginia Tech University, site of a 2007 massacre that killed 32 people, said on Thursday that a police officer and potentially one other person had been shot in an incident on campus.
A police officer has been shot. A potential second victim is reported, the university said on its Twitter feed.
The school's newspaper, Collegiate Times, reported that the police officer was dead.
MSNBC reported that the incident occurred after a traffic stop and that the suspect was still at large.
The school described the suspect as a white male in gray sweat pants and a maroon sweat shirt.
Stay indoors. Secure in place, the school's message said.
The incident brought to mind the April 2007 massacre, when a mentally ill student killed 32 people and wounded 25 others before committing suicide on the school's rural campus, located in the Shenandoah Valley roughly 250 miles (400 km) from Washington, D.C.
It was the deadliest shooting incident by a single gunman in U.S. history, and prompted a tightening of state and federal gun-control laws.
The school was criticized for its slow response to the incident and has since put a campus-wide alert system in place.
(Reporting by Andy Sullivan; editing by Philip Barbara)