Russia on Friday was mourning more than 50 people who died in a Siberian coal mine disaster, though the discovery of a rescue worker presumed dead was being hailed as a miracle.

The accident on Thursday at the Listvyazhnaya mine in the Kemerovo mining region saw smoke fill the site after an apparent gas explosion.

After initially reporting that six rescuers had died during attempts to reach miners, officials said Friday that one had been found alive after spending the night in the mine and was taken to hospital for treatment.

There were 285 people inside the Listvyazhnaya coal mine, in the Kemerovo region near the town of Belovo, when the accident occurred There were 285 people inside the Listvyazhnaya coal mine, in the Kemerovo region near the town of Belovo, when the accident occurred Photo: RUSSIAN EMERGENCY SITUATIONS MINISTRY via AFP / Handout

Acting emergencies minister Alexander Chupriyan called the survival of medic Alexander Zakovryashin "a miracle" and paid tribute to those who had died.

"Rescuers, just like miners, did their duty to the end," he said, and their names "will remain forever in our memory."

News of his survival was a small consolation for a community devastated by the loss of 51 lives, including those of 46 miners, in the worst mining accident in Russia in more than a decade.

Officials said it appeared the accident at the mine had been caused by a methane explosion.

There were 285 people inside the Listvyazhnaya coal mine, in the Kemerovo region near the town of Belovo, when the accident occurred There were 285 people inside the Listvyazhnaya coal mine, in the Kemerovo region near the town of Belovo, when the accident occurred Photo: RUSSIAN EMERGENCY SITUATIONS MINISTRY via AFP / Handout

Investigators launched probes into possible safety violations and senior managers at the facility were arrested.

Flags flew at half-mast outside official buildings in Kemerovo and grief-stricken relatives of the victims wept outside the snow-covered mine site.

"I can't carry on," one woman said, as families gathered in sub-zero temperatures.

Map locating Belovo in Siberia where dozens of miners were unaccounted for on November 25 after an accident. Map locating Belovo in Siberia where dozens of miners were unaccounted for on November 25 after an accident. Photo: AFP / STAFF

A former worker at the mine, Denis Timokhin, told independent TV channel Dozhd that safety violations were frequent at the facility, accusing management of forcing miners to work despite high methane concentrations.

"If you don't want to work, quit," he said. "No safety protocols, all sensors are plugged with bags."

The search and rescue effort had to be called off because of the threat of an explosion at the mine The search and rescue effort had to be called off because of the threat of an explosion at the mine Photo: AFP / Alexander PATRIN

Accidents are a part of life in the mining region, and some residents in the village of Gramoteino next to the mine laid flowers at a memorial dedicated to rescuers killed in a previous mine accident in 2000.

Miners described a frantic scramble to evacuate as the mine filled with smoke with more 285 people underground.

"I stretched out my hands, they couldn't find me on their own, because the visibility was bad," one miner said on state television. "They grabbed me... I didn't understand who it was and where they were pulling me."

Around 50 people were hospitalised following the accident.

Russia's Investigative Committee, which probes major crimes, opened a criminal case and said three people had been detained on Thursday including the director of the mine and his first deputy.

"During the initial investigation, it was established that the detainees violated industrial safety requirements," the committee said.

On Friday, investigators opened another probe against two officials of the local branch of state safety watchdog Rostekhnadzor, accusing them of failing to conduct proper inspections of the mine.

The governor said officials launched checks at all mines in the region.

Mining accidents are fairly common in Russia as a result of poor safety standards, a lack of oversight of working conditions and ageing Soviet-era equipment.

The Listvyazhnaya mine, near the town of Belovo, was set up in 1956 and is owned by the SDS-Ugol holding group controlled by influential businessman Mikhail Fedyaev.

Ilya Shumanov, director at Transparency International in Russia, said there was little chance of the holding's owners facing any consequences.

"It is obvious the owners of SDS holding have nothing to worry about," he said on messaging app Telegram.

A methane blast in 2004 killed 13 people at the mine and another explosion at the site killed five people in 1981.