China's state news agency now says 30 workers have been killed and 149 are missing after an explosion in a coal processing facility in northeastern Heilongjiang province.
Xinhua originally said the death toll was 40.
Xinhua says the blast was reported Sunday night at the Dongfield mine. More than 200 miners were working but only 42 managed to escape.
Rescue workers have gone into the mine to search for survivors.
Mines in China are widely regarded as the world's most dangerous. Many devote little attention to safety standards resulting in frequent cave-ins, explosions, floods and fires.
Some information for this report provided by AFP.