MOSCOW (Reuters) -- The death toll from the Siberian coal mine disaster at the weekend has risen to 43, Russian news agencies have quoted emergency officials as saying.
Forty-seven people were still missing at Russia's largest coal mine Raspadskaya after the country's deadliest mining disaster in three years.
Prime Minister Vladimir Putin had arrived in the coal-rich area in central Siberia and visited injured survivors in a hospital, the news agencies said. He was due to travel to the mine in the city of Mezhdurechensk.
More than 350 miners were underground when two explosions hit Raspadskaya, about 3,000 kilometers east of Moscow, over the weekend. Many of them managed to escape.
Aman Tuleyev, governor of Kemerovo region, said time was running out to rescue those trapped in areas of the mine where anti-flooding systems had failed.
The first explosion rocked the mine just before midnight on Saturday, May 8.
Valery Korchagin, Emergencies Ministry spokesman in the region, said 19 of the dead were rescuers who went into the sprawling mine after the initial blast.
News agencies have quoted Emergencies Minister Sergei Shoigu as saying that a sudden burst of methane and coal dust could have caused the disaster.
Mine explosions and other industrial accidents have prompted repeated calls from Russia's leaders for improvements to creaking infrastructure and stricter adherence to safety rules. Kremlin critics say little has been done.
The Raspadskaya mine has reserves of some 450 million tons of coal and produced 8.9 million tonnes in 2007, according to company officials. Raspadskaya is part-owned by steel-and-mining firm Evraz Group.