Russian Prime Minister Vladimir Putin demanded on Thursday a speedy completion of investigations into the blasts which killed at least 67 miners at the Raspadskaya coal mine in Western Siberia in May.
Russia's emergency officials say at least 23 miners are still missing from the two blasts that rocked the mine near the town of Mezhdurechensk on May 9.
"There has still been no final investigation... into the causes of the two explosions. Specialists will continue to work until all circumstances of the incident are established," Putin told a meeting in the west Siberian town of Novokuznetsk.
He told the Russian industrial safety watchdog that this work should be conducted quickly and professionally.
"The schedule [of the probe] cannot be extended interminably," he said.
Putin said analysis of the Raspadskaya tragedy had shown that the coal mining industry badly needed "systematic change."
Earlier this month, the Russian industrial safety watchdog extended the probe into the incident until the end of August.
The accident at the Raspadskaya coal mine is believed to have been caused by poor observation of safety regulations.
The Russian industrial safety watchdog detected over 1,400 safety violations at the mine in 2009 and in January-April 2010 and suspended production five times.
NOVOKUZNETSK, June 24 (RIA Novosti)
