At least 52 people have died in a blast inside a coal mine that took place in Russia’s Siberia region on Thursday, TASS news agency reported. Six rescuers were also among those killed in the explosion.

“According to the preliminary data, there were no survivors in the coalmine,” an unidentified official from the emergency services told the news agency.

A spark had led to a methane gas explosion and subsequent fire at the Listvyazhnaya mine in Siberia’s Kemerovo region on Thursday, AP reported.

A ventilation shaft in the mine was filled with the gas, which suffocated the miners, Reuters reported, citing an investigative committee.

Dozens of people rescued after the explosion were hospitalised. Four of them were in a critical condition, according to the news agency.

The explosion on Thursday was the most deadly mine accident in the country since 2010, AP reported. In that year, 91 people had died in two gas explosions and a fire at a mine in the same region.

A criminal investigation has been launched into fire safety violations at the Listvyazhnaya mine, AP reported. The director of the mine and two managers have been detained.

Russia’s President Vladimir Putin described the accident as a “great tragedy”, the BBC reported. He also offered condolences to the families of the deceased and ordered officials to help the injured, according to AP.