Putin noted the highly combustible materials used to convert the mall from a Soviet-era confectionary factory and the absence of a functioning fire safety system, saying that investigators will track down all those responsible.

Emergency officials reported that 58 bodies have been recovered and that rescue workers were still searching for six more in the city that is 3000 kilometres east of Moscow. They said 41 of the victims were children.

One protester at the rally, Igor Vostrikov, addressed deputy governor Sergei Tsivilyov, saying the families of the victims think the death toll is much higher than authorities have stated because the entire cinema burnt down.

"We're not calling for blood," he said. "The children are dead, you can't give them back. We need justice."

When Tsivilyov dismissed the comments as "a PR stunt," Vostrikov shouted that he has lost his wife, sister and three daughters, aged 2, 5 and 7, in the fire.

"They died because they were locked in a movie theater," Vostrikov told the Dozhd television station. "They were calling from there, asking for help: 'We're locked in, we're suffocating!' No one helped because when the blaze broke out, everyone ran away."

The impromptu protest reflected residents' deep frustration with the official response to the tragedy. The local governor has still not visited the site of the fire or met with the relatives, and Putin waited a day before travelling to Kemerovo and declaring nationwide mourning.

Facing public outrage, the Kremlin issued a statement Tuesday, declaring Wednesday a day of mourning.

Another deputy governor, Vladimir Chernov, told the rally in Kemerovo that unconfirmed reports of hundreds of deaths at the mall were untrue and said he was ready to resign if people wanted him to.

"Resign, resign!" the crowd chanted back.

Kemerovo's mayor asked the rally to nominate representatives to visit the morgue to check for themselves that the authorities were not hiding the truth about the deaths. A dozen protesters did so, and Putin met with them in the lobby, telling them to "not even doubt" that the culprits will be punished.

Responding to their calls to oust longtime Kemerovo regional Governor Aman Tuleyev, Putin said he would make a decision following a probe conducted by a team of 100 federal investigators.

"The investigators will check the entire chain, starting from those who issued permissions and ending with those who were responsible for safety," Putin said in remarks broadcast by state TV stations.

In an apparent attempt to deflect Putin's anger, Tuleyev blamed "the opposition" and "local busybodies" for fomenting the protest in Kemerovo.

In Moscow, St Petersburg and many other cities across Russia, tens of thousands were bringing flowers and soft toys to makeshift memorials to the fire victims.

"I mourn together with all the people," said the 28-year old computer expert Alexei Ivanov in St Petersburg. "I think the reason for that tragedy is irresponsibility and corruption."

Russian state television on Tuesday showed footage from inside the charred movie theater, where the roof had entirely collapsed. Investigators said emergency exits were blocked and a security guard turned off the public announcement system when he received a call about the blaze.

The victims included six fifth-graders from the town of Treshchevsky outside Kemerovo who were watching the Peter Rabbit computer-animated film and found the doors at the movie theater locked.

One of the trapped girls, Vika Pochankina, called her aunt saying they can't get out and asking to tell her mom that she loved her.

Yevgeniya Oganisyan, aunt of young fire victim Viktoria Pochankina, wrote on her page in the Russian social network VKontakte that she was "waiting for a miracle but it didn't happen."

"Why did this torment happen to you, our angel? You deserved a happy, joyful life," she wrote.

Alexander Bastrykin, chief of the Investigative Committee, the country's top criminal investigation agency, told Putin on Tuesday that the fire alarm had not been operational for two weeks and a security guard who failed to activate a parallel warning system couldn't provide a "reasonable" explanation for his actions.

He said investigators believe the blaze could have been sparked by a short circuit or an fire.

Investigators arrested the mall's director and four others who were responsible for fire safety. The director, Nadezhda Suddenok, told the court that she believed that the fire was caused by arson. She said one of her employees said flames first erupted in the children's game room, quickly engulfing the rubber foam gear.

The Investigative Committee is probing a Ukrainian blogger, Yevgeny Volnov, who posted his prank call to Kemerovo's morgue on YouTube, in which he was posing as an emergency official claiming that 300 people died in the fire.

AP