(Reuters) - Norfolk Naval Shipyard in Portsmouth, Virginia, was placed on lockdown on Thursday after reports of an active shooter, but authorities later said it was a false alarm.

After sending a SWAT team to the U.S. Navy facility, Portsmouth police declared that there was no shooter in the building where the report originated, spokesman Lieutenant Bryant Hall said.

The report was a false alarm, he said.

The shipyard later posted on its Facebook page that the facility had returned to normal operations. “Reports of an active shooter were deemed a false alarm. Lockdown conditions on the base have been lifted,” the statement said.

It had earlier told personnel to shelter in place and had cautioned that the alert was not a drill.