The miners fought to escape from the shaft while rescuers outside struggled to reopen the pit head, Lanzhou City Government deputy secretary-general Yan Chenglu said.

The miners appeared to be in good physical condition when they stepped out of the pit and were sent to hospital for a medical check.

“We guessed it was a landslide and not a gas blast or flood because there was no water and no smell of gas in the shaft,” a rescued miner told Xinhua.

An estimated 1.4 million cubic metres of mud slid and blocked the mouths of the main pit in Deshun Coal Mine Fields at around 10am on Wednesday, trapping the 16 miners underground and burying a number of houses, Xinhua reported.