MOSCOW, Oct. 30 (Xinhua) -- A floating dock accident injured four workers at a plant in Russia's Murmansk region, where aircraft carrier Admiral Kuznetsov was repaired, local news reported Tuesday.

The PD-50 floating dock tanks were abnormally filled during a power failure and the bridgehead abruptly went under water, RIA Novosti news agency quoted a plant representative as saying.

Four workers sustained non-life threatening injuries when the floating dock was flooded.

The aircraft carrier suffered no damage. It was towed to a regular berth to continue the repair work.

The PD-50, one of the world's largest floating docks, was built in 1980 in Sweden. It was designed for repairing large surface ships and submarines.