At least 37 people are confirmed to have died in a fire that tore through a shopping centre in the Siberian coal-mining city of Kemerovo.
At least 64 people are missing, including 41 children, and parts of the building are in danger of collapse.
Video posted on social media showed people jumping from windows to escape the flames on Sunday.
As many as 660 emergency personnel have been deployed in the rescue effort.
The cause of the blaze is not yet known but authorities have launched an investigation.
Kemerovo, a key coal-producing area, lies about 3,600km (2,200 miles) east of Moscow.
“According to preliminary information, the roof collapsed in two cinemas,” Russia’s Investigative Committee said in a statement.
The 37 bodies found are difficult to identify, said Mr Dedyukhin, but nine of them are of children.
Andrei Mamchenkov, deputy head of Russia’s National Crisis Management Centre, said a search was under way for 41 children.
Another source told the agency there was practically no chance of finding survivors.