KRASNOYARSK, September 3 (RIA Novosti) - One worker was killed and six injured after a gas blast at an open-pit coalmine in Khakasia, a Russian republic in south Siberia, a local emergencies official said on Wednesday.

Tuesday's explosion, caused by a gas leak, triggered a fire that spread over an area of 40 sq m. "Seven people were injured as a result and hospitalized, and one of them died in intensive care," the official said.

An excavator operator and his helper lost consciousness, apparently due to methane poisoning. The operator later died.

A commission of the industrial safety regulator Rostekhnadzor and rescuers are working at the site, said Dmitry Kudryavtsev, head of information at the Siberian emergencies center.

"Such conflagrations occur at open-pit coalmines from time from time. Experts are trying to determine what exactly caused it this time," Kudryavtsev said.