Naval Base San Diego was briefly placed on lockdown late Thursday morning after an unspecified security alert.
On-base security received a report of “suspicious activity” at an administration building about 11:17 a.m., officials said.
A lockdown was ordered out of an abundance of caution, officials said, and personnel were advised to seek shelter and remain in place.
According to a later posting, “base security secured the scene and are investigating the cause of the alert” and there was “no significant threat to personnel.” Officials did not provide details of the reported suspicious activity.
Normal operations resumed shortly before noon, they said.