The director of the Russian coal mine where two explosions killed at least 66 miners earlier this month resigned Tuesday after sharp criticism from Prime Minister Vladimir Putin.

"Raspadskaya coal mine director Igor Volkov today wrote a letter of resignation on his own will," said Galina Kovalchuk, a spokeswoman for the mine's administration.

Meanwhile, Vladimir Markin, head of Russia's Investigative Committee, also ordered discussion of possibly bringing Volkov and other mine directors to trial.

Volkov's resignation came a day after Putin gruffly lashed out at him and said industrial safety regulators had called for his resignation during the past year over "numerous violations."

Two methane explosions hit the Raspadskaya coal mine, Russia's largest, in the Siberian city of Mezhdurechensk on May 8, killing 66 and injuring about 100 others. Twenty-four miners remain trapped under the debris.

The RIA Novosti news agency reported that the Russian safety watchdog detected more than 1,400 safety violations at the mine in 2009 and the first four months of 2010, and previously suspended its production five times.

The Russian Technical Supervisory Authority, or Rostekhnadzor, filed four cases last year for Volkov to be sacked, but he received small fines only.