A spokesman for the local Emergencies Ministry in Siberia's Kemerovo region said the water was needed to dissipate and drain accumulated gases after the accident Saturday, RIA Novosti reported Tuesday.
Seventy-seven miners were working underground at the mine when smoke spread through the tunnels. Sixty-nine people were evacuated.
The water was pumped into the mine except for the area where four missing miners could be trapped, the official said.
"We have injected 7,300 cubic meters [about 1.8 million gallons] of water while we need a total of 7,600 cubic meters [about 2 million gallons]," the spokesman said.
After all the water is pumped into the mine, rescuers will resume searching for miners, the spokesman said.
A criminal investigation was started into charges of safety rule violations during mining operations, RIA Novosti said.