At least 100 people have died in China as a result of heavy rains which have also put the massive Three Gorges hydroelectric system on flood alert.
The huge city of Chongqing has been badly disrupted
More than 80 other people are missing in south-western Sichuan province after days of rain which local officials described as the heaviest in years.
Landslides and flash floods have destroyed houses and crops and left hundreds stranded.
The heavy rain eased on Tuesday, as rescue teams tried to reach survivors.
China regularly suffers storms and severe flooding in its summer rainy season, and more than 800 people have died due to severe weather this year.
More than 450,000 people have been evacuated and 127,000 homes destroyed or damaged, the China Daily reported.
In Sichuan and nearby Chongqing, entire communities have been marooned.
The worst-affected area is said to be the city of Dazhou, which has been hit with 360mm (14.4 inches) of rain, and has lost all its road links.
"There have been a lot of heavy mudslides and landslides. It is a serious situation in some counties," an official surnamed Liu at the Sichuan disaster relief bureau told the French news agency AFP.
"In Dazhou city there are around 3,000 people trapped by mudslides. In that city around 10,000 are trapped altogether. Local officials and troops are trying to evacuate people in dangerous places," he said.
The Chinese authorities put an initial estimate of the cost of flood damage in the region at hundreds of millions of dollars.
To the east of Sichuan, the massive Three Gorges dam project was closed to shipping for the first time since it began operations earlier this year.
Water flow at the dam has surpassed the warning levels of 45,000 cubic metres per second and is expected to reach 60,000 cubic metres per second on Wednesday, Xinhua said.