The U.S. Marine Corps Air Ground Combat Center in Twentynine Palms was on lockdown Monday morning, officials said.

At approximately 9 a.m., there were anonymous reports of shots fired at the location, the Provost Marshal of the Military Police Department told KTLA.

Out of an abundance of caution, all personnel were asked to shelter in place, the department said.

“At this time, we can confirm that a weapon was inadvertently discharged,” the training center said in a tweet just before 1 p.m.

The lockdown was lifted as of 12:20 p.m.

There were no reports of injuries.

No further details were immediately available.