A nearly four-hour lockdown of Dover Air Force Base after a report of a suspicious person was lifted Thursday afternoon.

The lockdown, which was put in place around 11 a.m., after someone reported a suspicious individual outside a building, was lifted at 2:40 p.m., base public affairs said. Normal base operations have resumed.

"We apologize for any inconvenience and confusion this response may have caused," Col. Randy Huiss, 436th Airlift Wing vice wing commander, said in a statement. "However, these measures were taken to ensure the safety of the base populace as we investigated the reports and found them to be false."

No additional details about the person were immediately available.

Base officials describe the lockdown as a "precautionary measure" but say all personnel are being told to shelter in place.