Russian news agencies reported Monday that at least 7 people had died from carbon dioxide poisoning in former tungsten mine in the Siberian region of Buryatia
Yevgeny Anoshin, spokesman for Rostekhnadzor, an agency that oversees mine safety, told ITAR-Tass that a group of miners had burned automobile tires on Friday deep in the closed mine to melt the extracted tungsten, a heat-resistant metal used to make light bulbs.
Since the mine lacked a ventilation system, the extremely high concentration of carbon dioxide became lethal, Anoshin said.
Seven other miners were saved by rescue workers, ITAR-Tass reported.
The mine, located seven kilometers (four miles) from the town of Zakamensk, was closed in 1996, but several residents continued to descend into the pit to extract tungsten.