BEIJING - THE number of people sickened by contaminated water in southern China has risen to 450, more than double the previously reported figure, state media said on Saturday.

The residents of two villages in southern Guangxi province began showing symptoms of poisoning last week, including swelling in the face and eyes, vomitting and blurred eyesight, the official Xinhua News Agency reported on Saturday.

Earlier this week, local officials had said 200 people became ill after drinking water contaminated by industrial waste from a nearby metallurgy company.

Tests on all 647 people in the two affected villages showed that four have been diagnosed with arsenic poisoning, Xinhua said.

A total of 55 people, 23 children and 32 seniors, remain hospitalised under observation. The remaining victims were given outpatient treatment and are recovering, the report said.

'The villagers were slightly poisoned. They can be cured in nine to 15 days with timely treatment,' Mr Ge Xianmin, head of the regional disease prevention and control institute, was cited as saying.

An investigation indicated the villagers' water source had been polluted by industrial waste from Jinhai Metallurgy Chemical, a branch of the state-owned Liuzhou China Tin Co. Ltd. The factory has been closed since the contamination was detected.

Authorities in the nearby city of Hechi said torrential rains from a recent typhoon caused wastewater from the company to overflow into nearby ponds and wells.

China's double-digit economic growth has come with a surge in toxic industries. The country has 16 of the world's 20 most heavily polluted cities.

China's Communist leadership has recently become more sensitive to the environmental cost of the country's economic boom after a series of high-profile pollution accidents along rivers disrupted water supplies to major cities. Farmers have protested over tainted water supplies and ruined land. -- AP