MIANYANG, CHINA - CHINA warned Friday that vital time was running out to save survivors of its devastating earthquake as it allowed the first foreign rescue teams to join the frantic search for life.

The government estimates the powerful quake has already killed some 50,000 people, and the chance of finding survivors buried in the rubble is diminishing by the hour.

Across the southwest province of Sichuan, teams of soldiers, volunteers and medics are clawing through mounds of shattered concrete that were once homes, schools and factories.

'The challenge is still severe, the task is still arduous and the time is pressing,' he said, quoted by China's state-run Xinhua news agency.

Rescuers on Friday pulled a child from the rubble of a collapsed school some 80 hours, state media said.

The child was found by rescuers searching the rubble of a school in the quake-devastated town of Beichuan, according to Xinhua.

The report said rescuers could hear more voices calling for help in the rubble and were 'expecting more miracles'. It did not specify the child's age or gender.

On Thursday, an 11-year-old girl was pulled from the rubble of another school in the badly hit town of Yingxiu.

Hopes fading

But officials have played down the chances of finding many more survivors, saying it would be miraculous for anyone to survive under the rubble for more than 72 hours.

And increasingly, rescuers have been dragging out bloodied bodies, bringing a new problem of disposal in communities that have almost nothing left.

Foreign rescue teams

After initially rebuffing offers of foreign aid teams, China has agreed to rescuers from Japan, Russia, Singapore and South Korea, and has issued a mass appeal for tens of thousands of shovels, hammers and cranes.

A Japanese team, the first to arrive, headed into a town where hundreds of families are reported buried, and a second Japanese team with sniffer dogs was en route.

South Korea is sending 44 experts and Singapore a team of 55 who helped in the aftermath of quakes in Indonesia, Pakistan and after the 2004 Indian Ocean tsunami.

They are bringing sniffer dogs, fibre-optic scopes, life detector systems and hydraulic cutters and spreaders.

Xinhua quoted a foreign ministry official saying it was the first time that China's government had accepted foreign professionals for a domestic disaster rescue and relief operation.

Death toll

State television, quoting figures from national quake relief headquarters, said the government estimates more than 50,000 dead.

The official confirmed death toll in worst-hit Sichuan province is 19,500, but several tens of thousands more are lying under debris.

Whole towns have been flattened, mountainsides sheared off, roads split in two, and countless thousands of buildings toppled or in danger of collapse.

The military, which has been spearheading rescue efforts, has scaled up its deployment, sending in extra transport planes, helicopters and troops.

They have been air-dropping tens of thousands of food packets, clothes and blankets, clearing roads, repairing bridges, sifting through the wreckage and ferrying the injured to hospital.

Rescue teams have also headed in from Taiwan - which China considers to be part of its territory - and Hong Kong.

Bai Licheng, a senior Communist Party official in Sichuan's Aba prefecture, warned of the risk of disease as bodies rot in the warmth.

'We are in urgent need of body bags,' he said in Yingxiu. 'Air-dropped food and drinking water are limited, and far from meeting the demand.'

Separately, the government was reported to be drawing up evacuation plans amid concerns that dams could collapse if rain persists.

The risk is especially acute in areas such as the counties of Wenchuan and Beichuan near the earthquake epicentre, state media said. - AFP