Medical reports issued by county authorities read like war bulletins. In the village of Gaozuitou at least 236 out of 285 children under the age of 14 tested positive for heavy metal poisoning. High lead concentrations were also found in at least 615 children in Sunjianantou and Madaokou villages.

However, County officials have rejected claims by Gaozuitou residents that their children’s illness was caused by the factory because it is located around 5 kilometres away. Locals have countered that their children show the same symptoms as the children living close to the plant; they have also demanded free medical tests.

Hospitals in the area have decided however to treat only patients with more than 250 mg per litre of blood even if anything above 100 is considered unsafe.

Faced with enraged villagers who clashed with police on Monday, the mayor of Baoji, Dai Zhengshe, promised to shut down the plant.

Residents however have complained that the promise was never fulfilled. Instead hundreds of policemen have been deployed along the roads around the smelter and in the vicinity of hospitals where children are being treated to prevent parents from talking to journalists.

In the meantime tensions are growing. Yesterday more than 200 residents took to the streets blocking the main road linking Baoji and the smelting plant, and stayed put even when police began arriving.

Increasingly embittered and angry, the residents are pledging they will fight the authorities for ruining their lives when they let the smelter go up and now for doing nothing to stop the pollution.

In Hengjiag, Wugang City (Hunan), another smelter was shutdown instead. It is responsible for manganese poisoning in at least 1,354 local children. Tests showed in fact that about 80 per cent of children examined had blood poisoning, Hengjiag village party chief Liu Zhongqi said.