The official death toll from the deadliest earthquake to hit China in three decades has risen to almost 29,000, a government spokesman confirmed today.
The final death toll is expected to hit 50,000 as rescue efforts continue.
Survivors were found today, five days after the disaster, including a German tourist who was pulled from rubble in Wenchuan after being buried for 114 hours, the official Xinhua news agency said.
Thirty-three people were dug out of the rubble in Beichuan, one of the worst hit areas. One man was rescued after being buried for 104 hours and troops evacuated 18 scientists trapped in a forest in Mianzhu.
Earlier a Chinese county near the epicentre of the 7.9 magnitude earthquake was ordered to evacuate amid fears a lake had burst its banks.
Rescue workers later returned to Beichuan county in Sichuan province, but many residents were too frightened to return, nervous about a lake formed after aftershocks triggered landslides blocking the flow of a river.
"After briefly evacuating, rescue work returned to normal at Beichuan," an official website said, blaming the evacuation on a false alarm.
A paramilitary officer said earlier that the likelihood of the lake bursting its banks was "extremely big".
The situation was "very dangerous because there are still tremors causing landslides that could damage the dam", said Luo Gang, a building worker who left the southeastern port city of Xiamen and rushed home to look for his missing fiancee.
Rescue work had been complicated by bad weather, treacherous terrain and hundreds of aftershocks. There has been growing concern about the safety of dams and reservoirs which have been weakened in the mountainous province of Sichuan, an area about the size of Spain.
In Sichuan and neighbouring Chongqing, at least 17 reservoirs have been damaged, with some dams cracked or leaking water. Several are on the Min River, which tumbles through the worst-hit areas between the Tibetan plateau and the Sichuan plain.
The Lianhehua dam, built in the late 1950s northwest of Dujiangyan, showed cracks big enough to put a fist in.
"When the dam is in this shape, we cannot feel relaxed," said farmer Feng Binggui who has moved from his village below the dam into the hills.
China is also on precautionary alert against possible radiation leaks, according to a government website. China's chief nuclear weapons research lab is in Mianyang, along with several secret atomic sites, but there are no nuclear power stations.
China has sent 130,000 troops to the disaster area, but roads buckled by the quake and blocked by landslides have made it hard for supplies and rescuers to reach the worst-hit areas.
Offers of help have flooded in and foreign rescue teams from Japan, Russia, Taiwan, South Korea and Singapore have arrived. About 4.8 million people have lost their homes and the days are numbered in which survivors can be found.
"Although the time for the best chance of rescue ... has passed, saving lives remains the top priority of our work," President Hu Jintao told distraught survivors.
The earthquake has also badly hurt livestock and crops in Sichuan province, and disinfection teams are spreading out to prevent more damage, officials said today. The earthquake killed about 792,000 of Sichuan's estimated 60 million pigs, Li Jinxiang, head of the veterinary department at the Ministry of Agriculture, told reporters.
Rescue work is still going on for thousands buried in rubble after the May 12 quake, but with bodies in mass graves and water supplies disrupted, efforts now also include disinfection campaigns to prevent disease spreading among animals and people.