Rescuers are pouring nitrogen into the mine to dilute the gas concentration. The process, which was started early on Sunday morning, needs to be continued for 24 hours before it is safe to enter the pit, said rescuers.
The blast happened at 8:43 pm on Saturday, when 20 people were working inside the mine. Three of them have been rescued.
The No.1 coal pit mined by Dahuangshan Yuxin Coal Mining Co Ltd is 120 km from Urumqi, Xinjiang's regional capital.
The company is owned by the sixth agriculture division of the Xinjiang Construction Corps, a paramilitary organization.