Beichuan, China - Thousands of Chinese earthquake victims fled areas near the epicenter Saturday, fearful of potential floods from a river blocked by landslides.

Soldiers carried older people out of Beichuan town - one of the areas hit hardest by the magnitude 7.9 quake Monday - while survivors cradled babies on a road jammed with vehicles and people. The death toll jumped to near 29,000.

A policeman told The Associated Press that rescue officials were worried that water from the choked river would inundate the town.

"The river was jammed up by a landslide, now that may burst. That is what we are worried about," the policeman said as he hurried by, not giving his name.

"I'm very scared. I heard that the water will be crashing down here," said Liang Xiao, one of the people fleeing. "If that happens, there will be over 10 yards of water over our heads."

The official Xinhua News Agency said earlier that a lake in Beichuan county "may burst its bank at any time," without giving details on why the water was rising. Residents left homes for higher ground, but 46 seriously injured were still at risk, the agency said.

The confirmed death toll rose Saturday to 28,881, Cabinet spokesman Guo Weimin said. The government has previously said at least 50,000 people were believed killed in the disaster.

Survivors were still being found under destroyed buildings five days after the quake. A 52-year-old man buried in the ruins for 117 hours was pulled to safety in Beichuan, just after a German tourist was found in Wenchuan county, Xinhua reported.

The vast majority of survivors are rescued in the first 24 hours after a disaster, with the chances of survival dropping each day, said Dr. Irving "Jake" Jacoby of the University of California, San Diego, who heads a medical assistance team that responded to a 1989 earthquake in California, Hurricane Katrina in 2005 and other disasters.

A person trapped but uninjured could survive a week or even 10 days and in extreme circumstances two weeks or more, he said.

Continuing aftershocks made digging through unstable buildings dangerous. On Friday afternoon, an aftershock rattled parts of Sichuan, burying vehicles on a road leading to the epicenter, Xinhua said.

Rescue teams from South Korea, Singapore and Russia got to work Saturday. They joined a Japanese specialist group, which was the first international rescue crew to arrive in the disaster area after China dropped its initial reluctance to accept foreign personnel.

A U.S. Air Force cargo plane loaded with tents, lanterns and 15,000 meals left Hawaii on Saturday, the first aid flight from the United States to help in Sichuan province. Another Air Force delivery was to fly in from Alaska.

The United Nations announced a grant of up to $7 million from its Central Emergency Response Fund, to be used by U.N. agencies and programs.

The government has not given a figure for the number of people left homeless, but Housing Minister Jiang Weixin said more than 4 million apartments and homes were damaged or destroyed in Sichuan province. He said the water supply situation was "extremely serious" in Sichuan, and not flowing at all in 20 cities and counties.

Caring for the untold tens of thousands or more survivors across the earthquake zone was stretching government resources.

Just north of the provincial capital of Chengdu, the town square in Shifang had become a tent camp for 2,000 people, and coordinator Li Yuanshao reported a lack of tents. Many people walked in from surrounding towns with few belongings.

"We brought almost nothing, only the clothes we are wearing," said Zhang Xinyong, a high school junior who walked several hours to the camp.

The Ministry of Health said there had been no major outbreaks of epidemics or other public health hazards in the earthquake area, according to Xinhua. By late Friday, hospitals in Sichuan had received 116,460 patients, including nearly 16,000 severely injured.