China stepped up the fight Thursday to stave off disease among over five million earthquake homeless as it tried to boost morale with plans to bring the Olympic flame through the disaster zone.

Ten days after the 8.0-magnitude earthquake, China was faced with the daunting challenge of how to reconstruct shattered communities after more than 74,000 people were confirmed dead or missing.

The health ministry said it had started sending 8,000 of the most injured people by trains and planes to other parts of China from the overwhelmed hospitals in worst-hit southwestern Sichuan province.

The government on Wednesday pledged more than 13 billion dollars for relief and reconstruction for the victims of the May 12 tremor, which caused destruction in an area three times the size of Belgium.

But for now, most of the 5.2 million earthquake displaced are crammed into tents or under simple tarpaulins where they face the threats of disease as well as simple boredom as they try to deal with their trauma.

Li Qiang, a senior health official for Sichuan's ravaged Shifang district, said that the decomposing corpses of millions of animals and people were adding to the health worries at the camps.

"And our public health services are no longer working. A big number of buildings are in ruins, computers are smashed and there's no electricity. So our alert system for epidemics is paralysed," Li told AFP.

The UN's World Health Organisation also identified preventing disease as the top concern, as it announced it was sending extra medical and hygiene supplies capable of treating 130,000 people.

"WHO has already identified that the key health issue in the earthquake's aftermath is to prevent and control communicable disease outbreaks," said Eric Laroche, assistant director-general for WHO's Health Action in Crises.

"But the longer-term challenge is how to best rebuild its damaged health infrastructure."

China faced some criticism for waiting three days before allowing in rescue teams. But medics from countries including Italy, Japan and Russia are now working on the ground, with US as well as the WHO experts also due.

At a makeshift housing camp in the Sichuan capital of Chengdu, youngsters with nothing to do passed time by having their blood pressure measured by an eager nurse, a pointless activity that was aimed at simply relieving boredom.

"Some are getting a little impatient," said Liu Haiyan, a 26-year-old English teacher who had volunteered to help out in the camp that is being set up for 1,000 people.

"They should arrange activities for them to do. Maybe sports events or singing or whatever."

In a bid to cheer up survivors, organisers announced that they would bring the Beijing Olympic torch through Sichuan province from August 3 to 5, making it the final stop before the Games open on August 8.

It had been scheduled to go to Sichuan earlier but the route was changed "to support the relief works in the quake-hit area," the Beijing Games organising committee said in a statement on its website.

The announcement came as the torch relay resumed in the eastern port city of Ningbo following a three-day suspension that was called as part of an unprecedented national mourning period for the quake victims.

The torch relay has been greeted by enthusiastic crowds throughout China, after a troubled international leg that was a lightning rod for protests over China's human rights record including its controversial rule in Tibet.

Tibet's government-in-exile has called for a halt to the protests as a mark of respect to the earthquake victims.

Meanwhile, hope has all but vanished for finding more survivors buried underneath the rubble of the earthquake.

Rescuers on Wednesday plucked to safety a woman who had been stranded for an improbable nine days in a water tunnel of a power plant.

Cui Changhui, 35, suffered multiple fractures but her condition was not life threatening, according to doctors.

"It's a miracle, absolutely," said Tian Yongming, a senior nurse at the Huaxi hospital in Chengdu where Cui is being treated.

"She has a strong desire to live. That's why she was saved after being trapped so long without food and water," Tian said, as quoted by state media.