MOSCOW - Two people were killed and four others injured on Sunday in a mine explosion in Russia's Far Eastern republic of Yakutia, the Emergency Situations Ministry said.

"Today, at the depth of 365 meters an accident occurred in ALROSA's mine under construction. At that time, there were 17 people there," the regional branch of the ministry said.

Twelve people escaped to the surface on their own.

All of the injured have been hospitalized, with one of them in critical condition, the branch said.

Local investigators, who were still looking for more details of the blast, said the explosion was caused by the ignition of a methane-air mixture.

ALROSA was a Russian diamond and mining giant.