A cave-in at a flooded coal mine in central China's Hunan Province Thursday has hampered efforts to rescue seven trapped miners.

The cave-in did not injure the rescuers but it has lowered the miners' chances of survival, rescuers and experts said.

In addition to pumping water out of the mine, the rescuers will have to clear the caved-in area before they can reach the miners.

Low levels of oxygen in the area the miners are trapped has increased the likelihood the miners will suffocate.

Still, rescuers have not given up hope and are installing more pumps to drain the mine.

Water inundated the Yide Coal Mine in Xiangtan County on Tuesday at 11:38 p.m., trapping the miners 89 meters below the surface.

A deputy mine manager led 27 workers safely out of the mine after the accident.