Thousands of Chinese soldiers arrived at the epicentre of a deadly earthquake Wednesday, in a desperate attempt to save thousands still buried under rubble. But with few tools available, troops were forced to dig through debris by hand.

Families were desperate to find trapped relatives, with time running out for those stuck under collapsed buildings.

"Yesterday my husband was calling for help, but today I don't hear anything," one woman told CTV's Steve Chao in Chengdu, the capital of Sichuan province.

"I think it's too late."

Soldiers also had to fix the Zipingpu Dam, located upriver from the city of Dujiangyan, because the earthquake had left it with "extremely dangerous" cracks.

There are also concerns closer to the epicentre in Sichuan province.

He Biao, director of the Aba Disaster Relief headquarters in northern Sichuan province, said the most dangerous problems are several reservoirs near Wenchuan.

"There are already serious problems with the Tulong Reservoir on the Min River. It may collapse. If that happens, it would affect several power plants below and be extremely dangerous,'' he said.

China's top economic planning body said Monday's 7.9-magnitude earthquake damaged 391 dams, most of which are small.

Watch dramatic amateur video of the quake

Death toll jumps

The official death toll rose Wednesday to 14,866, said state-run news agency Xinhua.

Xinhua also said nearly 26,000 people remain buried in debris and another 14,000 are missing.

CTV's Steve Chao said the death toll will no doubt rise.

"In some of the hardest hit areas... rescue crews have yet to reach them," said Chao. "Those places have populations of tens of thousands so people just don't know at this point how many people are trapped under the debris."

Chao said officials finally reached the town of Yingxiu Wednesday and found 80 per cent of the population -- more than 7,000 people -- dead.

At least eight schools near Chengdu also collapsed following the quake, killing thousands of children, said Chao.

"Many parents have been camped out at these schools, waiting for days, just for a glimmer of hope that their children will be pulled out alive," he said.

Chao said there have been some "miracle stories," including that of a three-year-old girl who survived after being protected by the bodies of her parents.

Fifty-thousand police officers and soldiers have been mobilized to sift through piles of concrete.

But even when survivors are found, crews have had to make heartbreaking choices.

Rescuers had to amputate the legs of one little boy who was found in the rubble.

The powerful earthquake struck at 2:28 p.m. local time Monday, when office buildings, factories and schools were full.

With a report by CTV's Steve Chao in Chengdu and files from The Associated Press