Thousands of people have protested in the Siberian city of Kemerovo, angry at Russian officials over the leisure complex fire that killed at least 64 people, 41 of them children.

President Vladimir Putin arrived in Kemerovo earlier and blamed “criminal negligence” for Sunday’s blaze.

Relatives say dozens of people – including children – are still missing.

Investigators say the fire alarm was switched off and exits blocked. Four people have been charged.

Another detained suspect – a guard from a private security firm – will be charged shortly, Russia’s Investigative Committee says.

A national day of mourning will be observed on Wednesday.

Several thousand people rallied outside the local government headquarters, saying that officials must be sacked over the fire safety shortcomings.

There were also some chants of “Putin resign!”

A woman in the crowd drew applause when she said “children called their parents, asked them for help, asked for the fire brigades to be sent in”.

Many demonstrators said they did not trust the authorities and did not believe the announced death toll was accurate.

Officials were booed when they urged the crowd to disperse, after the protest had already lasted seven hours, Russia’s RIA news agency reported.

Regional Deputy Governor Sergei Tsivilev then got down on his knees to beg forgiveness, and was applauded by the crowd.

President Putin expressed indignation over the disaster – though he did not speak to the crowd.

“People, children came to relax. We are talking about demography and are losing so many people because of what? Because of criminal negligence, sloppiness,” he said.

•Text (excluding headline): BBC.