A Royal Navy sailor has pleaded guilty to shooting an officer to death and firing at three other crewmen on a British nuclear submarine.

Able Seaman Ryan Donovan admitted Monday that he killed Lieutenant Commander Ian Molyneux on the HMS Astute, while the submarine was docked in the port city of Southampton in April. Donovan entered his plea at Winchester Crown Court and will be sentenced at a later date.

The 23-year-old sailor also admitted to the attempted murders of three other crewmen . Donovan fired an SA80 rifle numerous times before the weapon was wrestled away from him.

The shootings took place as local dignitaries, including Southampton's mayor, were being given a tour of the submarine during a goodwill visit to Southampton.