Thousands of people are being evacuated from around a lake and a river threatening to burst in southwest China's earthquake zone, geological experts and soldiers said on Saturday.

In Chaping of the Beichuan County, authorities said they are preparing to explode the embankment of a lake due to heightening lake burst risks.

Hundreds of rescuers and local residents have been told to leave the areas to be affected by the explosion, and seek shelter on higher grounds.

Earlier Saturday, soldiers at the area reported 46 seriously injured people needed to be evacuated.

In the Hongguang Township in the Qingchuan County, authorities are evacuating about 2,000 people downstream, as experts with the Sichuan land resources department warned the rising risk of the Qingzhu River.

Multiple landslides set off by the powerful earthquake blocked parts of the river and formed a large stretch of water, which experts with said exceeded 10 million cubic meters.

More debris slides caused by aftershocks were likely to continue to push the water level up, experts said.

"If the water level rises by another two to three meters, it will overflow and threaten more than 2,000 people who are staying in shelters after the earthquake downstream," one of the experts said.

Water had already overflowed into the streets of a neighboring village in the Qianjin Township, he said.

Experts said the lake embankments were very loose after being shaken by the earthquake, which also heightened the risk of a burst.

"It the lake bursts, it will form at least a 40-kilometer water way, and the results will be grave," he warned.

(Xinhua News Agency May 17, 2008)