Approximately 20 used shell casings were found Monday morning outside Strong Hall on the University of Kansas campus, KU Public Affairs officials said.

KU Public Safety officers have since retrieved the shell casings and “have found no indications a weapon was fired anywhere near Strong Hall,” according to a message sent out to KU students, faculty, staff and university affiliates around 10:45 a.m. Monday.

“At this time, it is believed these shell casings were deposited by a person or persons wishing to make a statement,” the release said.

Strong Hall, KU’s main administration building, houses the offices and support staff for the university’s chancellor, provost and registrar, among other high-level administrative positions.

The shell casings “do not pose a threat to health or safety,” the press release said.