Three miners trapped for more than four days in a flooded mine shaft in northeast China were rescued Saturday as authorities battled to reach another 23 workers still underground, state media said.

The illegally operating mine in Heilongjiang province flooded on Tuesday when 45 workers were in the pit, the official Xinhua news agency said. Nineteen miners managed to escape shortly after the accident.

Rescuers have been pumping water out of the mine and by Saturday afternoon had drained 56,150 cubic metres (about 2 million cubic feet) and lowered the water level inside the pit by more than 10 metres (33 feet), Xinhua said, citing rescuers.

On Wednesday, the government in Boli county -- where the mine is located -- said it had sacked two top officials for their roles leading up to the mishap, including the county head.

Provincial authorities had ordered work at the mine owned by the Hengtai Coal Mining Co. to halt in 2007, but on August 16 the owner illegally restarted production, Xinhua said.

The flood occurred after workers mistakenly drilled into a neighbouring mine that had been filled with water, it said.

China's coal mines -- which have a dismal safety record -- have been hit by a series of accidents in recent years as demand for energy has spiked. In July, a coal mine flood in southwest Guizhou province killed 23 workers.

Last year, 2,433 people died in coal mine accidents in China, according to official statistics -- a rate of more than six workers per day.

Labour rights groups, however, say the actual death toll is likely much higher, partly due to under-reporting of accidents as mine bosses seek to limit their economic losses and avoid punishment.