A 19-year-old sailor on a Russian nuclear submarine stole a machine gun and shot eight crewmen to death before barricading himself in the vessel's torpedo section at a northern port, officials said Friday.

Alexander Kuzminykh, a draftee who's been in the navy since last year, went on a shooting spree overnight on the vessel in Severomorsk, near the northern city of Murmansk, the Defense Ministry said in a statement. Eight sailors were dead and the stand-off was continuing.The submarine was of the Bars class, a nuclear-powered fleet submarine normally armed with nuclear cruise missiles and torpedoes, navy officials said.

There were no missiles on the submarine because it was in port. Still, the torpedo compartment where Kuzminykh was holed up did contain conventional explosives, the Interfax news agency reported.

The shooting rampage began when Kuzminykh seized a machine gun from a guard, killing him and then fatally shooting seven more crew members, the Defense Ministry said.

The account gave no word on what might have prompted his actions. However, the Interfax news agency said Kuzminykh had been in detention on disciplinary charges when he seized the weapon.

The commander of the Russian navy, Adm. Vladimir Kuroyedov, flew to the port to handle the situation.

Kuzminykh's family members, including his mother and a brother, were flown to the site, news reports said.

Officials tried to contact the sailor and appealed to him to surrender, but he was not responding to their calls.