A local emergencies ministry official in Siberia's Kemerovo region told UPI Tuesday that the water, which would also drain accumulated gases following Sunday’s explosion in the Prokopyevsky district, was not pumped into the area where the four missing miners were believed to be located.

“We have injected 7300 cubic meters [about 1.8 million gallons] of water while we need a total of 7600 cubic meters [about 2 million gallons],” the spokesman told the news wire service.of its work at the mine in the Kuzbass coal basin.

He added that once the water was pumped in, a rescue effort would continue to find the missing group.

According to Xinhua, the Emergency Situations Ministry said Sunday that 77 miners were working underground when smoke spread throughout.

Sixty-nine people were safely evacuated to the surface. A prior BBC report indicated that the four killed miners died from smoke inhalation, though it was unclear from where the smoke came.

In the meantime, Xinhua reported Monday that investigators had opened a criminal probe into the blast. Law violators could face up to eight years in prison for the incident under Russia’s criminal code.

The names of the men killed and missing have not been released, though rescuers told the news outlet that they were shaft miners aged 27 to 45.

Victims’ families will reportedly receive 3 million rubles in aid (about $US99,130).