A Russian nuclear submarine caught fire at a shipyard in Russia's northern city of Murmansk on Thursday, according to local emergencies department.

A Russian nuclear submarine caught fire at a shipyard in Russia's northern city of Murmansk on Thursday.

"No deaths or injuries have been reported. There is no threat of nuclear pollution," the department said in a statement.

The authorities said fire safety violations during the K-84 Yekaterinburg nuclear submarine's routine maintenance works were the most likely cause of the fire at a floating repair dock.

Spokesman of the Russian Northern Fleet Rank Vadim Serga said the wooden scaffolding around the submarine first caught fire, which spread to the submarine's light outer hull.

"There is no possibility of fire burning through the hull and no threat to on-board equipment," Serga was quoted by RIA Novosti news agency as saying.

The K-84 Yekaterinburg nuclear submarine is one of Russia's seven Delta-IV class submarines in service, which are all deployed in the Northern Fleet.