A Darwin naval base went into lockdown recently after an armed intruder stole military-issue weapons and tied up a sailor during a raid on a navy patrol boat. Police have called the incident a breach of national security.

The break-in at the HMAS Coonawarra base, was by a single intruder armed with a gun and wearing a balaclava boarded the Armidale class patrol boat Bathurst, which was moored at the base.

A Northern Territory Police spokesman said a crewman on board was assaulted and tied up before the intruder broke into the boat’s armoury. He said two pump-action shotguns and a dozen 9mm pistols were taken.

An Armidale class patrol boat would carry a stock of machine guns, assault rifles, shotguns, 9mm pistols and ammunition in its armoury. A “cache” of weapons appeared to be missing. The Royal Australian Navy bases 10 of its 14 patrol boats in Darwin.