A blast at a coal mine in northern Russia on Monday left 10 people dead and seven missing, Russia's Emergency Situations Ministry said.
Nearly 300 rescuers are searching for the missing men at the Vorkutinskaya mine in the Komi region, the ministry said in a statement.
The blast occurred in the mining area because of a build-up of methane, the ministry said.
Russian investigators opened a probe into suspected violation of safety rules at the mine, the Investigative Committee said in a statement.
There were 22 men in the mine at the time of the blast that happened because of the build-up of methane, the ministry said. Two of them were able to get out of the mine on their own and three were rescued.
Russian news agencies quoted Emergency Situations Minister Vladimir Puchkov as saying that there's still a hope that the missing men would be found alive.
"We're moving step by step in scouring throughout the mine, and I hope that the seven men are alive," Puchkov said, according to the Itar-TASS news agency.
Deadly accidents at coal mines are frequent in Russia because of negligence and lax safety regulations. In January, nine people died in two separate mine accidents.