Blood tests show that 70% of children under 14 are affected
Two government officials in central China are being investigated after more than 1,300 children fell sick with lead poisoning, the local government says.
The pair from the environmental agency in Wugang city, Hunan province, are suspected of dereliction of duty.
Last week, two executives of the Wugang Manganese Smeltering Plant were held over the poisonings and the plant shut.
Another smelter in Shaanxi province was closed days earlier after 600 children there developed lead poisoning.
Emissions from the smelting plants are thought to be behind the poisonings in both cases.
"Following a preliminary probe, a case of dereliction of duty has been established against two officials from the city environmental protection bureau," the Wugang government said in a statement posted on its website late on Friday.
The Wugang smelter had been operating since May last year without approval from the environmental bureau. It was closed on 13 August.
Officials said 1,354 children - 70% of those under 14 living in four villages near the plant - were found to have excessive levels of lead in their blood.
Lead poisoning can cause a range of health problems, from learning disabilities to seizures. Children under six are most at risk.
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