At least 64 people were killed by a fire in a shopping mall in the Siberian city of Kemerovo, Russia's Emergency Situations Ministry said on Monday.
The fire, one of the deadliest in Russia since the end of the Soviet Union, swept through the upper floors of the Winter Cherry shopping mall where a cinema complex and children's play arena were located.
According to news agencies, the preliminary findings of an inquiry said the fire started around 1100 GMT in one of the cinema halls and destroyed more than 1,000 square metres of the centre.
The local office of Russia's emergency services ministry said the fire broke out on the third and top floor of the mall, where firefighters were struggling on Monday to clear the rubble.
The Investigative Committee said it has detained four people for questioning, including one of the mall's tenants, but would not immediately give the cause of the fire, which started on the top floor on Sunday evening. The investigators have launched a probe into possible negligence and violations of the fire safety rules.
Around 120 people had been evacuated from the burning centre, rescuers said on Sunday.
"This shopping centre on several floors was packed with people midday 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.
Russia's minister of emergency services, Vladimir Putchkov has gone to Kemerovo, RIA Novosti said.
Winter Cherry was one of Kemerovo's most popular entertainment centers for children, with its own indoor skating rink, petting zoo and trampolines. Kemerovo residents said the mall was packed with children and their parents.
The mall opened in 2013 with an overall area of 23,000 square meters. It has a parking lot for 250 cars, shopping centres, a bowling club, a children's centre, a cinema, and a petting zoo.
More than 200 animals at the petting zoo were also killed in the blaze.
Photograph: Russia's minister of emergency services