KITTERY, Maine (AP) — The Portsmouth Naval Shipyard Fire Department has responded to a report of another potential fire aboard the USS Miami submarine, but it turned out to be a false alarm.

The shipyard says an alarm activated at just before 9 a.m. Wednesday aboard the sub, but there was no fire. A shipyard statement says it appears to be a "faulty alarm activation."

The nuclear-powered submarine was severely damaged by a fire that broke out on May 23 while the ship was in dry dock for an overhaul at the shipyard in Kittery.

The Navy is investigating the cause of the fire, the extent of the damage and whether the Los Angeles-class submarine can be repaired.