A nuclear submarine caught fire in a shipyard in Russia's northern province of Arkhangelsk on Tuesday but there were no weapons on board, Russian news agencies reported.
The Emergencies Ministry declined comment on the reports of the fire at the Zvyozdochka shipyard, where the agencies said the 155-metre-long (just over 500 feet) 949 Antei submarine was being repaired. There was no word of any casualties.
"There is a fire on the submarine. We are fighting the fire now," a shipyard source told Interfax news agency.
RIA quoted a spokesperson at the shipyard as saying there were no weapons on board the submarine.
A source told TASS news agency the submarine's nuclear reactor had been shut down prior to the blaze.
"The active zone of the reactor was unloaded at the start of repairs a few years ago," the source said.
The news agency reports said the fire had started during welding, causing insulation materials to catch fire.
A similar blaze in 2011 nearly led to a nuclear disaster as a blaze engulfed a nuclear-powered submarine carrying atomic weapons, a leading Russian magazine reported months after the blaze, contradicting official assurances that it was not armed.