Montana State University police are searching buildings and telling people to stay inside after receiving a report of two men carrying a rifle on campus.
An alert sent out by the university Wednesday morning says police received a report the men were crossing 11th Avenue in Bozeman and heading toward the center of the Centennial Mall.
The Bozeman Daily Chronicle reports one man is wearing a hunter's orange hoodie and the other a green or gray jacket and a baseball hat.
Officers are advising people on campus to stay inside and lock their doors.
Bozeman police say nearby schools have been locked down. Police officials say the measure is a precaution and they have no reason to believe a gunman is heading toward the schools.