Devastated relatives are now burying their dead
More than a dozen mine officials have been arrested, Chinese state media have reported, after a landslide engulfed a village, killing at least 178 people.
The local Communist Party head has been sacked over Monday's incident in Shanxi province, news agency Xinhua said.
Thousands of rescue workers are combing through the debris in Taoshi, in which hundreds more victims may be buried.
Frequent mining accidents in China are blamed on lax safety standards and ageing infrastructure.
More than 3,000 rescue workers are at the site, near the city of Linfen, recovering bodies from the debris with the help of 160 diggers, Xinhua reported.
But hopes of finding any more survivors are fading four days on from the accident. It is not known how many people are still missing.
Rescuers have already covered about 90% of the area, Xinhua said.
Earlier in the week, government officials were quoted as saying hundreds of people could be dead, but they later denied such statements.
Thirteen officials from the Tashan Mining Co, which ran the illegal iron ore operation, have now been arrested, Xinhua reported.
In addition, the head of the local Communist Party and other senior local officials were dismissed, the agency said.
"It is the most grave accident that involves the largest death toll so far this year," said Wang Jun, director of the State Administration of Work Safety.
"The rising accidents disclose local governments' poor supervision on work safety. Those responsible must be dealt with seriously."
The torrent of sludge buried the village of 1,000 people, including a market that was packed with people attending a fair, the China Daily newspaper reported.
Witnesses said that the mud appeared to be more than 20ft (6m) deep in some places.
State media said that the mining reservoir was decommissioned in the 1980s, but had recently been put back into use after a new owner took over the mine.
The mine's safety certificate was revoked in 2006, it said.
Analysts say the disaster highlights China's failure to enforce safety standards at its notoriously dangerous mines, and also the unsound state of many of its bridges, dams and other ageing infrastructure.