Rescuers on Tuesday searched for four missing miners nearly a day after a methane gas explosion in a Siberian coal mine killed at least 106 people in Russia's deadliest mining disaster in a decade.

As many as 200 workers were in the Ulyanovskaya mine in the coal-rich southern region known as the Kuzbass at the time of the blast, which occurred early Monday at a depth of about 270 metres, emergency and regional officials said.

Buses carrying rescuers enter the Ulyanovskaya mine Monday.
(RTR Russian Channel/Associated Press)

Sergei Cheremnov, a spokesman for the regional government in Kemerovo where the mine is located, told the Associated Press that company officials and safety experts, along with a British citizen and his interpreter, were in the mine examining a British-made hazard monitoring system just before the blast occurred.

The British man and the interpreter were later confirmed dead.

Cheremnov said it was unclear exactly what he was doing in the mine, but reports said he was a British expert on mine safety who dealt with methane explosions.

Work 'complicated by … obstructions'

The massive mine is operated by Yuzhkuzbassugol, an affiliate of Russian coal and steel company Evraz Group SA, which acquired a 50 per cent stake in the company in 2005.

No one answered repeated calls to the company. However, company spokesman Eduard Sivtsov earlier told Russian television channel NTV that rescuers were checking a large section of the mine for survivors.

"Their work is complicated by a great number of obstructions," he said.

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.

Blast blamed on quota systems

In recent years, conglomerates such as 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 each will receive at least $25,000 in compensation, Kemerovo Gov. Aman Tuleyev was quoted by ITAR-Tass news agency.