At least 205 people are dead, and hundreds more are missing, in catastrophic floods in north-western China which some local reports describe as the worst in the area for more than a century.

Casualties will certainly increase as the investigation continues

Shaanxi flood control centre spokeswoman

The area has seen a week of torrential rain, and in the worst affected area - south of the city of Xian - close to half a metre of rain fell in two days, in what is normally an arid part of China.

Rivers that had been dry for years turned into raging torrents, sweeping away roads, destroying tens of thousands of homes, and bringing down a railway bridge in Xian just three minutes after a train crossed it.

A huge rescue operation is under way, including army units specially formed to deal with flood emergencies, but the number of dead is expected to rise.

Farmers drowned

Some of those swept away by the floodwaters were farmers who had planted their crops in the bottom of dried out riverbeds - taking advantage of three years of drought in the area.

The main east-west railway line linking China's coast to its vast inland provinces has been cut, power supplies have been interrupted, and thousands of acres of farmland are flooded.

The flooding in Shaanxi alone has washed out 13 bridges, 30 kilometres (20 miles) of highways and railway lines and has wrecked 29 hydropower stations, said a spokeswoman for the Shaanxi provincial flood control centre.

"Casualties will certainly increase as the investigation continues," the spokeswoman said.

Several provinces have been severely hit by the floods:

• At least 150 people are reported dead, 266 are missing and more than 110,000 need emergency aid in Shaanxi province
• Twenty-seven people are reported dead and 15 missing in Sichuan province, including 14 in the worst-hit city, Suining, and 210,000 people need emergency aid
• Two people are reported to have been killed and four injured in Gansu province
• In Hubei province, Guizhou province and Chongqing municipality 29 others were reported dead

And in the northwest region of Xinjiang, rains have destroyed 500 homes and 1,600 hectares (4,000 acres) of cropland, the official Xinhua news agency reported on Wednesday.

Annual danger

China is often crippled by floods in the summer and there are fears that this week's floods could herald a repeat of those in 1998, when more than 300,000 soldiers were mobilised to overcome floods in which at least 2,000 people died.

The government has since taken extra measures to battle the disaster - banning tree felling, forming special army units to combat flooding on major rivers, and pressing ahead with the controversial Three Gorges Dam.

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