SAN DIEGO—A reported sighting of a man possibly armed with a gun at Naval Medical Center San Diego Friday prompted a nearly two-hour lockdown and a multi-agency search that turned up no such threat.

The security scare at the Balboa Park hospital began about 10:30 a.m. Friday, authorities reported.

Authorities directed staffers and patients in parts of the facility to shelter in place while San Diego police and military officers searched the complex, Navy spokesman Brian O’Rourke said.

After finding no firearm threats at the Bob Wilson Drive medical center, police issued an all-clear shortly before 12:30 p.m., O’Rourke said. Normal hospital operations then resumed, he said.

One person was taken into custody for questioning in the case, according to the Navy spokesman. It was unclear how the detainee might have been connected to the incident.