Some 400 staff were on board when one of the vessel's sections caught ablaze.

Fire erupted in No.1 Power Compartment of Soviet-Russian aircraft carrier Admiral Kuznetsov in Murmansk at 10:15 Moscow time Dec 12.

"Air carrier is undergoing repairs in a dry dock in Murmansk. Fire is thought to be caused by welding works. Three workers are missing, fire spread from initial 20 square meters to some 120 square meters of Energy Block and probably, neighboring compartments. Diesel fuel is burning, not clear if it's a spill or fuel is stored in tanks," Maritime Bulletin said on December 12.

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Some 400 workers were on the aircraft carrier when the fire erupted. They were evacuated, while six people sustained injuries, one of them is in serious condition. One person is missing, according to Russian news agency TASS.

Most of the victims were poisoned by combustion products, while and one person suffered a head injury.