"At this time, we can confirm the deaths of 37 people in the fire at the Kemerovo shopping centre", Russia’s Investigative Committee said, according to TASS news agency.
Images on Russian television showed thick black smoke pouring out of the Winter Cherry shopping centre in the city of Kemerovo, which also boasts a sauna, a multiplex cinema and a bowling alley that was packed with people on a Sunday afternoon.
Investigators had initially reported five people dead including a child and another 30 people injured and taken to hospital.
As the new death toll was announced, a source in the local rescue services said 69 people including 40 children were reported missing, the RIA Novosti agency reported, while the Investigative Committee said it was "verifying information that 35 people could be missing".
The preliminary findings of the inquiry said the fire started around 1100 GMT in one of the cinema halls and destroyed more than 1,000sq.m of the centre, news agencies reported.
"The roof collapsed in two theatres in the cinema," the Investigative Committee said.
Around 120 people had been evacuated from the burning centre, rescuers said.
"This shopping centre on several floors was packed with people mid-day Sunday. No one knows exactly how many people there were inside when the fire broke out," Alexandre Eremeyev, an official with the local Russian emergency services ministry, said in a statement.
"Where to look for people? How many are there? That has greatly complicated the work of the firefighters," he said, adding that the thick smoke was also hindering their task.
Some 300 firefighters and rescue personnel were rushed to the scene and the fire was brought under control around 1730 GMT, local emergency officials said.
Russia’s minister of emergency services, Vladimir Putchkov has gone to Kemerovo, RIA Novosti said. Vietnamnews.