Rescuers using infrared cameras to peer into darkness at a wrecked mine in eastern China have found eight surviving miners trapped for five days after a collapse so violent it registered as a seismic event.

The Christmas Day disaster at the gypsum mine in Shandong province killed at least one worker. Nine others remain missing.

Gypsum is a soft sulfate mineral that is widely used in construction.

Infrared cameras detected the surviving miners waving their hands and rescuers were drawing up plans to pull them to safety, said state broadcaster China Central Television (CCTV). The rescuers sent supplies underground to the trapped men, Xinhua News Agency said.

The workers were weak with hunger but otherwise were in good health and told rescuers they were in passages underground that were intact.

Two days after the collapse, the owner of the mine, Ma Congbo, jumped into a well and drowned in an apparent suicide. Four top officials in Pingyi county, where the mine is located, have been sacked.

The collapse was so massive that the national earthquake bureau detected a quiver with a magnitude of 4.0 at the mine site.

China's mines have long been the world's deadliest, but safety improvements have reduced deaths in recent years. Last year 931 people were killed in mine accidents throughout China, drastically down from the year 2002, when nearly 7,000 miners were killed.