UPDATE 3-Methane blast at Mechel coal mine injures 17

(Adds company statement, whereabouts of CEO Zyuzin, injury details)

MOSCOW, July 29 (Reuters) - A methane blast ripped through a Siberian mine belonging to Russian coal producer Mechel MTL.N on Tuesday, just days after government criticism wiped out roughly half of the company's stock value, or around $8 billion.

Seventeen workers are receiving treatment for burns after being evacuated from the Lenin mine in the town of Mezhdurechensk, Mechel said in a statement.

Coal production has stopped at the mine, which accounts for about a quarter of the output from Mechel’s Southern Kuzbass subsidiary, its principal coal producer.

The company’s general director, Igor Zyuzin -- who was singled out last week for scathing criticism by Prime Minister Vladimir Putin -- has flown to the scene of the accident, Mechel said in a statement.

Rostekhnadzor, Russia’s mining safety watchdog, has begun an investigation into why safety regulations had again been breached at the mine, a spokesman for the watchdog, Evgeny Anoshin, told Reuters.

On May 30, a tunnel collapse at the same mine trapped six workers 400 metres below ground. Five of the men died despite frantic rescue efforts lasting several days.

The safety watchdog has previously cited Southern Kuzbass, the subsidiary, for breaching regulations, but has allowed coal production at its mine to go on.

Since Thursday, Mechel has twice faced attacks over its financial practices from Putin, whose claims that the company evaded taxes and unequally priced its mineral resources have caused the stock to plummet [ID:nL8573139].

On Thursday and again on Monday, Putin’s comments led the company’s shares to fall more than 35 percent on the New York Stock Exchange, with a partial recovery seen on Friday.

Apart from rigorous tax and antitrust probes, Russian companies that fall foul of the government often face pressure from safety officials.

Forty-one workers were in the mine when repair work led to the explosion, and all of them climbed out of the mine on their own, the Mechel statement said.

Four of the miners are in critical condition in the emergency ward of a local hospital, while the rest are being treated in the trauma ward, Interfax reported, citing an emergency official on the scene. (Additional reporting by Tatyana Ustinova, editing by Will Waterman)