Police in Washington D.C. say that an 85-minute lockdown at American University's campus was prompted by a call from a student who saw a man wearing a gun holster on a university shuttle bus. 

D.C. police Lt. Jesse Porter told the Associated Press that no weapon was ever displayed, no threats were made, no crime was committed and there were no arrests or injuries.

Washington Police spokesman Officer Hugh Carew says the department received the report of a gunman at about 7:40 p.m. and that officers searched the campus in the northwest section of the nation's capital. 

The university posted an all-clear on its website about 9:25 p.m., saying the campus could resume normal operations.

The Associated Press contributed to this report.