Eight people have been safely rescued while 21 remain trapped in a coal mine after a flooding incident in northwest China's Xinjiang Uygur Autonomous Region, local authorities said on Sunday.

The rise of water level in the mine slowed on Monday as seven sets of drainage equipment started pumping water out.

Rescuers said they monitored the oxygen level in the flooded mine to be above 20 percent.

All the trapped miners had been located on Sunday, scattered among three different operating platforms 1,200 meters below the ground. 

The flooding occurred at 6:10 p.m. on Saturday when Fengyuan mine in Hutubi County, Changji Hui Autonomous Prefecture, was undergoing a technological upgrade. A total of 29 miners were working underground at the time.

China's Ministry of Emergency Management said it had sent experts and rescue teams to the site. A total of 1,484 people, including 854 professional rescue workers, joined the ongoing rescue and search operation.

The incident cut off power and communication systems, local authorities said, adding that the complex topography had complicated the rescue operation. 

Per reports, rescue workers tried to contact the trapped miners, and air supply was also provided. 

(With input from Xinhua)