41 children were among those killed in a fire at a shopping mall complex in Kemerovo in Russia, local media has reported.
Russian President Vladimir Putin said earlier that "criminal negligence" was a factor behind the blaze that killed 64 people in the Siberian city.
Mr Putin's comments, aired by state television, come after investigators said the public address system had been turned off and fire exits had been illegally blocked.
Russia's Investigative Committee said there had been "serious violations" at the Winter Cherry mall, which is situated in an industrial coal-mining city 3,600km east of Moscow.
Up to 11 people are still believed to be missing.
Parents of missing youngsters have been posting pictures in an attempt to find them.
In comments quoted by the TASS news agency, Mr Putin said during a visit to the scene: "What is happening here - this was not a combat situation, not an unexpected methane outburst in a mine.
"People came to rest, children. We talk about demographics and lose so many people because of what? Because of criminal negligence and carelessness."
In this Russian Emergency Situations Ministry photo on Sunday, March 25, 2018, smoke rises above a multi-story shopping center in the Siberian city of Kemerovo. Picture by: AP/Press Association Images
Russian television broadcasts showed people leaping from the windows of the building which was engulfed in black smoke.
People are said to have taken refuge in the toilets, sealing gaps around the door with wet clothes.
Health minister Veronika Skvortsova said an 11-year-old boy was being treated in hospital after jumping from the fourth floor. His parents and younger brother died in the fire.
During a televised briefing on Monday, emergency situations minister Vladimir Puchkov did not confirm how many children were among the dead.
He said six bodies were yet to be recovered.
Shopper Ivan told the Siberian Times he had been at an indoor ice rink with his children.
"As we rushed out of the building, I saw a teenager falling out of a window," he said.
"'There was no fire alarm, no automatic fire extinguishing."
The Investigative Committee, which handles major crimes in Russia, said 10 people were being treated in hospital. It added that 44 had sought medical treatment.
Four people, including one of the shopping centre's tenants, have been held for questioning.
The committee did not comment on the cause of the fire.
A petting zoo was among the centre's attractions. All of its 200 animals - including foxes, deer, meerkats, squirrels and hamsters - are thought to have perished.
The blaze erupted on the top floor of the four-storey shopping centre near a cinema complex and children's play area on Sunday afternoon.
The building, which was converted into a shopping centre from a former confectionery factory in 2013, is said to be in danger of collapse.
More than 1,000 square metres of the centre is thought to have been destroyed. The roofs of two cinema screens also collapsed during the blaze.