The director of Russia’s Raspadskaya mine has quit and been charged with criminal negligence in relation to two methane gas explosions that claimed at least 66 lives at the mine this month.

Russian Prime Minister Vladimir Putin earlier called for tighter state control of mines and singled out mine director Igor Volkov as responsible for safety violations.

Volkov is being charged with violations of federal fire regulations and negligence leading to fatalities, according to the investigative committee of the prosecutor’s office.

Raspadskaya spokesperson Galina Kovalchuk said Volkov’s resignation was accepted and Raspadskaya chief executive Gennady Kozovoy has taken over his duties.

Two methane explosions rocked the Raspadskaya mine in the Kemerovo region a week ago, killing at least 66 people and leaving over 100 injured while 24 people are still missing.

Over a hundred violations had reportedly been detected at the mine by federal safety inspectors over the past year.

A large number of miners and their families protested last week after alleging they had been forced to disable safety equipment in order to meet production targets.