A methane gas explosion deep in a Siberian coal mine killed at least 78 people and left another 50 trapped Monday in Russia's worst mining disaster in a decade.
Among the missing were company officials and safety experts who had been inspecting a British-made hazard-monitoring system, said Sergei Cheremnov, a spokesman for the regional government in Kemerovo where the mine is located about 1,850 miles east of Moscow.
A British man and his interpreter were among those killed, he said. It was unclear what the two were doing in the mine.
Up to 200 workers were in the Ulyanovskaya mine when the explosion occurred about 885 feet underground in the coal-rich southern region known as the Kuzbass, emergency and regional officials said. At least 75 people were rescued.
Rescuers were checking a large section of the mine for the missing people and were in contact with some of the surviving miners, officials said. It was unclear if the survivors were in immediate danger.
"Their work is complicated by a great number of obstructions," Eduard Sivtsov, a spokesman for Yuzhkuzbassugol, the company that operates the mine, told NTV.
Russian television broadcast footage of one miner, blackened and semiconscious, lying on a stretcher on his way to a hospital. At least five miners were injured.
President Vladimir Putin ordered Emergency Situations Minister Sergei Shoigu to travel to the area, and the industrial regulatory agency Rostekhnadzor sent investigators.
The mine is located in the city Novokuznetsk, the site of two of the deadliest mine disasters in the past decade. In 2004, a blast at a mine on the outskirts of the city killed 47 workers and in 1997, a methane explosion killed 67.
Russia's mining industry fell into disrepair when government subsidies dried up after the Soviet collapse. At least 30 workers died in Russian mining accidents last year, including 25 killed in a fire at a Siberian gold mine.
In the U.S. last year, 47 workers died in coal mine accidents, including 12 in the Sago Mine accident in West Virginia. It was the U.S industry's deadliest year since 1995, when 47 were killed.
In recent years, conglomerates like Evraz SA have bought up coal mines and similar enterprises and consolidated operations, selling raw and semi-processed material to steel smelters, electricity producers and other major industry. Some government officials have accused private companies of cutting corners on safety measures to save money.
Alexander Sergiev, chairman of the Independent Coal Miners' Union, said the Ulyanovskaya mine operated with new equipment, but he said that human and natural factors always created the potential for accidents. He said miners may have encountered a pocket of methane while working and he called for new safety regulations to help prevent such accidents.
"It's necessary, in my view, to pass legislation forbidding underground coal mining without the required (ventilation) from the surface for methane," he told Ekho Moskvy radio.
Sergiev also blamed the blast on quota systems that encourage miners to work faster and harvest more coal, potentially leading to carelessness.
The families of the dead will each receive at least $25,000 in compensation, Kemerovo Gov. Aman Tuleyev was quoted by ITAR-Tass news agency.
Nobody answered repeated calls to Yuzhkuzbassugol. The company, an affiliate of Russian coal and steel company Evraz Group SA, is Russia's leading producer of coking coal, producing 14 million tons in 2005, according to the Evraz Web site.