A section of the mine was flooded after power outages just after 6pm local time on Saturday afternoon when 29 miners were working at the mine in Hutubi province in Xinjiang, the report said.
In a separate report, state media Global Times said 12 of the miners trapped were found in the mine as of Sunday and are expected to be rescued, while nine more workers have not been located.
Chinese mines are among the deadliest in the world.
Ten gold miners were declared dead in January after an explosion at a mine in Shandong province in China.
In December last year, 23 people were killed after being trapped in a mine in the southwestern city of Chongqing. Three months earlier, 16 people had died in a separate coal mine in the same area.
State media on Sunday said rescue efforts in the Xinjiang mine were continuing.