The New Nation - Internet Edition

AFP, Yingxiu

Time was running out Thursday to save survivors of China's massive earthquake which has left more than 40,000 people lying dead or buried under rubble in its stricken southwest.

Experts said the search-and-rescue operation was entering its most crucial phase yet four days after the 7.9-magnitude quake struck, with the chances of finding survivors diminishing by the hour.

As the military ramped up its rescue efforts with more troops and aircraft, a new threat emerged from creaking dams and reservoirs shaken by the quake.

State-run television said authorities had found "dangerous situations" at more than 400 reservoirs-two of them major-across five provinces.

The epic scale of Monday's quake is becoming clearer as teams hike into the remote epicentre, where whole towns were levelled causing untold deaths.

"As the destruction was severe and people were buried somewhere deep below ground, that's really trouble," Zhang Zhoushu, vice director of the state-run China Earthquake Disaster Prevention Centre, told AFP.

"If there are some survivors under such conditions, it would be a matter of luck or a miracle."

China has rebuffed most foreign offers to send rescuers, but said Thursday it would accept a Japanese team flying in with sniffer dogs.

"Most people are saved in the first three or four days," Willie McMartin, director of the British-based charity International Rescue Corps, told AFP in Hong Kong where his team is trying to get permission to enter China.