They say eight people are still missing after a massive surge of water in the turbine hall at the Sayano-Shushenskaya plant in Siberia.
Rescue and clean-up operations are continuing, but officials say chances of finding any survivors are slim.
The cause of the accident on the plant on the Yenisei River remains unclear and an investigation has been launched.
See graphic of stricken power station
There have been claims from Chechen websites that Islamist militants were responsible for the accident.
Those suggestions have been rejected by Kremlin sources as «idiotic», and investigators have reportedly found no traces of explosives at the site.
Previous reports suggested a transformer exploded during repairs, destroying three generating units and leading to the flooding of a turbine hall.
'Billions of roubles'
Prime Minister Vladimir Putin visited the site on Friday.
He promised relatives of the victims to pay 1m roubles (($30,000) each in compensation.
Mr Putin also compared the current state of Russia's infrastructure to that of a wartime frontline, and promised to match the company's payouts with government compensation.
Russian Emergencies Minister Sergei Shoigu said it would take at least a week to assess the damage from the blast, adding that repairing the turbine hall alone could cost 40bn roubles ($1.3bn; Ј762m).
But he said it would still be worth doing the repairs, because the dam — undamaged by the blast — had accounted for 80% of the construction cost.
The plant's owner, RusHydro, has said the damage will run into «billions of roubles» and take several months to repair.
Some 40 tonnes of transformer oil leaked into the river after the explosion, killing fish and raising fears of chemical pollution.
Situated some 3,000 km (1,900 miles) east of Moscow in the remote mountain region of Khakassia, the Sayano-Shushenskaya plant is expected to remain closed for some time.
One of the world's largest hydro-electric plants, its dam is 245m (800ft) high and stretches 1km (0.6 miles) across the Yenisei river.
Opened in 1978, the station provides a quarter of RusHydro output and is a major power supplier to at least two smelters owned by United Company RUSAL, the world's largest aluminium producer.
