Rescuers on Sunday were trying to reach 21 coal miners who were trapped by an underground flood in China’s northwest, a state news agency reported.

The mine in Hutubi County in the Xinjiang region flooded at about 6:10 pm on Saturday, the Xinhua News Agency said. It said eight people were rescued.

China’s coal mines are among the world’s deadliest, regularly suffering explosions and gas leaks despite repeated safety crackdowns.