By CNN Wire Service.

Investigators have found "absolutely nothing" to substantiate a report that gunshots were fired in the basement of a Naval Medical Center San Diego on Tuesday morning, Navy Capt. Curt Jones said. However, authorities still are going though the building, and it will take a long time to finish their search, he said. He said he'd characterize the person who made the report as "someone who thought they heard something and made reports."

There are no reports of injuries or deaths so far in connection with reports of gunshots at Naval Medical Center San Diego, military officials said.

Authorities responded to reports of three gunshots fired around 8 a.m. (11 a.m. ET) Tuesday in the basement of Naval Medical Center San Diego's Building 26, medical center spokesman Mike Alvarez said. Alvarez said the incident is being treated as if it's an active shooter situation.

The child care facilities at the medical center "are currently secured," Naval Base San Diego said around 9 a.m. (noon ET) on its Facebook page. "All children are accounted for and safe. The entire complex is secured."

The original Facebook message read:

"**!ATTENTION!** An active shooter has just been been reported in building #26 at Naval Medical Center San Diego. All occupants are advised to run, hide or fight. All non-emergency response personnel are asked to stay away from the compound, located at 34800 Bob Wilson Drive, San Diego, CA 92134"