This is a breaking news story. Check back for updates.

UPDATE 5:46 p.m. EDT: One of the suspects was playing with an airsoft pistol, which prompted the incident to be investigated, NBC San Diego reported.

"He was actually firing shots of the air soft pistol out of the window toward a mirror in the parking lot," Base Commanding Officer Scott Adams told the station. 

The shots caused a tenant at the base to call authorities. Once the suspect realized NCIS was mobilized in response, he and a friend called their commanding officer. The two were then arrested and taken into custody.

UPDATE 3:57 p.m. EDT: Two suspects are in custody in connection with the incident, according to KPBS

Original story:

Portions of a San Diego naval base were under a shelter-in-place order Thursday afternoon amid reports of a man with a gun at Naval Base Point Loma.

The incident was reported around 10:55 a.m. local time, spurring an investigation by naval officials, NBC San Diego reported. Individuals on part of the base were ordered to shelter in place.

People are being asked to avoid the portion of Naval Base Point Loma where the incident occurred, according to the San Diego Union-Tribune. Naval security forces and the Naval Criminal Investigative Service are leading the probe, the paper reported.

Naval Base Point Loma is home to the Space and Naval Warfare Systems Command and several submarines, according to NBC San Diego.