A slew of calls reporting an active shooter on University of Pittsburgh campus were found to be a hoax Monday night, according to police.

The calls resulted in the campus’ Hillman Library on Forbes Avenue to be evacuated and systematically searched around 11 p.m., Pittsburgh news outlets said.

According to a post on Twitter from Pittsburgh Public Safety, an officer shot through a locked door to gain access to the library.

“There is no evidence of any other shots fired,” the post said.

Pittsburgh Public Safety updated the public around midnight Tuesday, also in a Twitter post.

“Upon investigation, there is no evidence of an active shooter and no victims. The building has been safely cleared,” the post said.

Students were told they could return to the building to retrieve their belongings at that time.

Communication from the university’s emergency system at 12:30 a.m. Tuesday informed students that officers responded to all locations mentioned in the calls, and that they were determined to be a hoax.