At least 53 people have died in a fire that tore through a shopping and entertainment complex in the Siberian coal-mining city of Kemerovo, BBC reported.
As many as 41 children may be among the victims, officials say, and more than 10 are listed as missing.
The blaze started on an upper floor of the Winter Cherry complex while many of the victims were at the cinema.
Video posted on social media showed people jumping from windows to escape the flames on Sunday.
"According to preliminary information, the roof collapsed in two cinemas," Russia's Investigative Committee said in a statement.
The cause of the fire is not yet known and authorities have launched an investigation.
Some 660 emergency personnel were deployed in the rescue effort. Firefighters tackled the blaze for more than 17 hours.
Kemerovo, a key coal-producing area, lies about 3,600km (2,200 miles) east of Moscow.