A report of a shooting at Naval Medical Center San Diego appears to be a false alarm, the US military indicated Tuesday.

Investigators have found nothing to substantiate one person's report that someone fired gunshots Tuesday morning at the San Diego facility's Building 26, which contains barracks, a gym and administrative offices, the CNN quoted Navy Capt. Curt Jones as saying.

However, authorities at the center's 78-acre campus still were going through the building late Tuesday morning, and it will take a long time to finish their search, he said.

One witness reported hearing three gunshots in the basement of the building -- separate from the main hospital complex on campus -- at about 8 a.m. PT (11 a.m. ET), Navy spokesman Kevin Dixon said.

That prompted a flurry of law enforcement activity, with military and local police searching the building as other officers took up positions nearby, directing pedestrians and cars away from the building in question.

The center, in its first Facebook post on the incident, said that "all occupants are advised to run, hide or fight."

After officers did a preliminary search, there were no reports of anyone injured, and there was no immediate evidence to suggest a gun had been fired, Jones said later in the morning.

Source: MENA