Four people have been killed and two others injured in an explosion at a copper mine in southeast Russia, a Russian news agency reported on Sunday.
The incident in the town of Gai, in the Orenburg region, occurred during the laying of explosives to extract copper, according to the report.
"Four people were killed. Two were injured and are in hospital in the city," a spokesman for Gaisky GOK, which owns the mine, told the Ria Novosti news agency.
Work in the mine was suspended while a team was dispatched to determine the cause of the incident, he added.