Moscow, Russia (CNN) -- Hazardous conditions inside Russia's largest coal mine forced officials to suspend efforts Sunday to rescue dozens of workers trapped inside after a pair of explosions, the country's Ministry for Emergency Situations said.

The explosions killed 12 people and wounded 41 others, the country's Prosecutor General's Office said. An additional 64 miners were trapped underground, as well as 19 rescuers who went to retrieve them.

Rescue operations were suspended Sunday because of limited visibility, the ministry said.

Three hundred and fifty nine people were working in the mine, near the western Siberian town of Mezhdurechensk, when a gas explosion occurred around 8:55 p.m. Saturday local time (12:55 p.m. ET).

More than 50 rescue workers descended into the mine to recover the victims when a second gas explosion occurred about four-and-a-half hours later -- at 1:25 a.m. Sunday (5:25 p.m. Saturday ET), officials said.

As a result, 19 rescue workers remained trapped in the mine.

Earlier Sunday, local officials blamed the accident on a partial rock collapse inside the mine.

Russian President Dmitry Medvedev pledged federal aid in responding to the disaster.

Mezhdurechensk is more than 2,300 miles east of Moscow.

"By all accounts, the situation is hard, very hard at the Raspadskaya mine. I would say, it is tragic," said Russian Prime Minister Vladimir Putin.

"The worst thing is that we can't send additional rescue forces to the mine in the absence of air ventilation. But we can't sit back and hope the situation will improve on its own. We must make maximum effort and do all we can to save the people."