Moscow: Investigators looking into a fire that killed at least 64 people at a busy shopping mall in the Siberian city of Kemerovo said on Monday that a security guard had turned off the fire alarm system and that exits had been illegally blocked.
The fire, one of the deadliest in Russia since the break-up of the Soviet Union, swept through the upper floors of the "Winter Cherry" shopping centre on Sunday afternoon where a cinema complex and children's play area were located.
Dozens of children were feared to be among the dead.
President Vladimir Putin, re-elected last weekend, has yet to speak publicly about the tragedy, which has stirred deep anger in Kemerovo, a coal-producing region about 3,600 km (2,200 miles) east of Moscow.
The Kremlin published a statement, saying Putin "expressed his deep condolences to the relatives and loved ones of those who died."
Russia's Investigative Committee, which handles major crimes, said it was trying to bring in the mall's owner for questioning and wanted to detain a security guard who had turned off the fire alarm system after learning of the blaze.
"Serious violations (of the law) took place when the mall was being built and when it was functioning. The fire exits were blocked," Svetlana Petrenko, a spokeswoman for the committee, said in a statement.
She said investigators, who have opened a criminal investigation into the blaze, were looking into other possible violations. Four people have already been detained, including the owners and lessees of outlets inside the mall.
Emergency services said they had extinguished the fire, but later said it had reignited in places, and that rescuers were struggling to recover bodies beneath smouldering rubble.
It was unclear if any people were still unaccounted for. Veronika Skortsova, the health minister, said from the scene that 11 people were in hospital, including an 11-year-old boy who was in a serious condition. Russian media said the boy had leapt from a window and that both his parents had been killed.
An unofficial list of those missing circulating on Russian media included more than 20 children, some as young as five. Mobile phone messages sent from one of those on the list, 13-year-old Maria Moroz, and published by Russian media, said: "We are burning. I love you all. This is perhaps farewell."
Alexander Lillevyali told online newspaper Meduza that he and his wife Olga had lost all three of their daughters, two of them aged 11 and one aged five, in the blaze.
He was cited as saying he had dropped off his daughters at the cinema and that one of them had phoned later to say the auditorium was filling with smoke and that they couldn't get out because the doors were locked.
He described how he had led rescuers up the stairs, but that they had been ordered to go elsewhere and that rescuers, citing rules, had refused to give him a respiratory mask.
"My daughters were left to burn because of their bloody rules," Lillevyali told Meduza.
Anna Kuznetsova, Russia's children's rights commissioner, said the fire had been caused by incompetence and that similar shopping centres across Russia should be urgently checked.
Witnesses told Russian media the fire alarm and sprinklers had failed to function and that many people had found themselves trapped because exit doors were locked.
Video footage from inside the mall after the fire broke out showed a group of people in a smoke-filled staircase trying to smash a fire exit door, which was jammed.
The Interfax news agency cited an unnamed local official source as saying the main theory being looked at was that the fire had been caused by an electrical short circuit.
However, it quoted Vladimir Chernov, the region's deputy governor, as saying on Sunday that the blaze had started when a minor had set fire to the foam on a trampoline in a play area using a lighter.
Other officials were quoted as saying the blaze may have been started by candles used in a children's celebration.
State TV said the mall had opened in 2013. Official documents showed it had last undergone a fire safety check in 2016.
The Kremlin rejected criticism from some journalists that state TV had been slow to publicise the fire.
Mourners left flowers near the scene of the blaze.
The fire was thought to be the deadliest since 2009 when 156 people were killed in the city of Perm when an indoor pyrotechnics display at a nightclub went wrong.