Officials at California State University, San Bernardino said the gunfire was reported at about 6 p.m. Wednesday.
At 10 p.m., university spokesman Joe Gutierrez said police officers were evacuating campus buildings and escorting students and faculty out, but he could not confirm that a shooting actually took place. No shooter has been found, reports CBS Los Angeles.
Although police did not believe there was an active shooter, students were asked to shelter in place.
The school about 60 miles east of downtown Los Angeles has about 20,000 students.
Taika Waititi Dances His Way Through the THOR: RAGNAROK Gag Reel
Marvel Studios: The First Ten Years - The Evolution of Heroes - Marvel's universe is vast and transcends both time and space. He said this after finishing his scenes with " Avengers 4 ", written and directed by the brothers Anthony and Joe Russo .
This article was originally published at 6:50 p.m. "Everyone not living on campus should immediately leave", the university said in a statement, adding that police would continue to monitor the campus.
Later, investigators did find evidence that a building's window had been struck by a bullet. The outside of a building had a single strike, but it was unclear whether it a gunshot, he said. There were no reports of injuries, Burguan said on Twitter. "Do not attempt to leave campus", the tweet said.
The shelter-in-place order remained in place for several hours.
All Wednesday night classes at the campus were canceled due to the incident.