Six men remain trapped underground one day after an illegal coal mine in Shanxi province flooded, the local government said on Wednesday.

Liu Xianyun, a production safety official in the city of Yangquan, said water levels in the mine had dropped by just over three meters as of Wednesday morning, as rescuers have been working to pump the water out.

More than 3,100 cubic meters of water have been pumped from the coal mine, and 375 cubic meters are being pumped out every hour, Liu said.