PORTSMOUTH, Va. — Bomb threats have continued to interrupt Navy facilities in Virginia this week. The latest came Thursday morning at the Norfolk Naval Shipyard in Portsmouth. Officials said in a statement that the threat was written on the wall of a bathroom in a complex of work trailers. Normal operations in that area of the shipyard resumed after a sweep found no bomb.

Authorities also found no bombs after telephone threats Wednesday that targeted Naval Station Norfolk and Joint Expeditionary Base Little Creek in nearby Virginia Beach.

Normal operations in Norfolk also were interrupted on Monday, when a sailor reported seeing a trespassing scuba diver near a pier. The sighting proved unfounded.