FIREFIGHTERS HAVE MANAGED to put out a huge fire that broke out on board a docked Russian nuclear submarine, after battling the flames all night as some crew members remained inside.

Officials insisted there was no radiation leak, and said the vessel’s nuclear-tipped missiles were not on board at the time.

The fire broke out Thursday at an Arctic shipyard outside the northwestern Russian city of Murmansk where the submarine Yekaterinburg was in dry dock. The blaze, which shot orange flames high into the air through the night, was put out this afternoon, but firefighters continued to spray the vessel with water to cool it down, Emergency Situations Minister Sergei Shoigu said.

Russian state television earlier showed the rubber-coated hull of the submarine still smoldering, with firefighters gathering around it and some standing on top to douse it with water. Most modern submarines’ outer hulls are covered with rubber to make them less noisy and more difficult for an enemy to detect.

Seven members of the submarine crew were hospitalised after inhaling poisonous carbon monoxide fumes from the fire, Shoigu said.

An unspecified number of crew remained inside the submarine during the fire, Defense Ministry spokesman Colonel Igor Konashenkov said in a statement. He insisted there never was any danger of it spreading inside the sub and said the crew reported that conditions on board remained normal.

Konashenkov’s statement left it unclear whether the crew were trapped there or ordered to stay inside.

Russia’s military says the blaze started on wooden scaffolding and then engulfed the sub’s outer hull. The vessel’s nuclear reactor had been shut down and its nuclear-tipped missiles and other weapons had been unloaded before dry-dock repairs, it said.

Toxic fumes from the blaze had spread to the town of Roslyakovo where the shipyard is located, but officials said there was no need to evacuate local residents.

The Yekaterinburg is a Delta-IV-class nuclear-powered submarine that normally carries 16 nuclear-tipped intercontinental ballistic missiles. The 166-metre (548ft) vessel has a displacement of 18,200 tons when submerged.

This video shows smoke and flames billowing from the vessel as it is doused with water:

(Video: AssociatedPress)