Beijing ? China has detained two factory officials after 1,300 children were poisoned by pollution from a manganese processing plant, days after emissions from a lead smelter in another province sickened hundreds.

Both cases have sparked unrest and come amid growing anger in China over public safety scandals in which children have been the main victims. Tainted infant formula milk and the mass collapse of schools in a huge earthquake last year have also provoked widespread dissent.

The latest incident involves the Wugang Manganese Smelting Plant in Wenping township, central Hunan province. It opened in May 2008 without the approval of the local environmental protection bureau, within 500 yards of a primary school, a middle school and a kindergarten.

Fears of poisoning began to spread among villagers in early July when many children became susceptible to colds and suffered fevers and other ailments, the official Xinhua News Agency said Thursday.