MOSCOW, Aug. 17 (Xinhua) -- At least eight people were killed and more than 50 others were still missing following a hydropower plant accident in Russia's Siberia on Monday.

    "Preliminary reports said eight people, working in the turbine room, were killed, 10 injured and 54 are missing," the RIA Novostinews agency quoted Vladimir Markin, spokesman for Russia's Investigation Committee, as saying.

    However, a senior local emergencies official Andrei Klyuyev said that up to 68 people were still missing.

    Dmitry Kudryavtsev from the regional Emergency Situations Ministry told the Interfax news agency that around 50 to 67 workers of the plant were unaccounted for.

    "The precise number of workers, who happened to be on the premises of the hydropower plant at the moment of the accident, is still unknown. The lists are being updated," he said.

    The accident occurred at Sayano-Shushenskaya plant, Russia's largest hydroelectric station, which was opened in 1978 and is located on the Yenisei River in East Siberia, the Itar-Tass news agency quoted Kudryavtsev as saying.

    The third and fourth culverts at the power station were damaged at around 04:49 Moscow time (0049 GMT) Monday, destroying walls and submerging engine room, said Kudryavtsev.

    One of the possible causes of the accident is a hydraulic surge, said Kudryavtsev.

    Electricity supplies were suspended to several major aluminum plants after the plant suspended production. Meanwhile, repair work has started.

    The accident has cut power supplies to homes and companies, and six factories in the nearby Altai region were shut down due to electricity shortage.

    Vasily Zubakin, head of RusHydro, owner of the Sayano-Shushenskaya plant, said that: "Replacing the turbine will take from 18 months to two years," and "the station's units that were not damaged could be restarted within 45 days."