Flooding is becoming an increasingly serious problem

The flood, which hit the county of Ziyang in Shaanxi province late last week, swept away thousands of buildings and triggered deadly landslides.

The latest deaths bring the number killed by flooding this year in China to nearly 650.

That's more than double the number killed in the same period last year and comes before the peak of the flood season.

Danger level

China's rainy season reaches its height in the next few weeks and officials are warning that water levels on both the Yangtze and Yellow rivers are already well above danger level.

China has been plagued by flooding for centuries, but major floods are becoming more and more frequent -- one reason is environmental destruction.

Two years ago more than 4,000 people died in China's worst flooding in half a century.

In its aftermath the government banned all logging on the upper reaches of the Yangtze river.

But they admit it will take decades, if not centuries, to repair the damage already done.