BEIJING (AP) — Medical tests have shown at least 121 children living near a battery plant in eastern China are suffering from lead poisoning, the latest in a recent string of such cases that have affected hundreds.

Two medical agencies tested 287 children younger than 14 years of age for lead poisoning and found 121 of them had excessive levels of lead in their blood, the government of Shanghang county in Fujian province said in a statement late Saturday. An investigation was ongoing, it said.

The discovery of clusters of lead poisoning in recent weeks has sparked unrest and growing anger in China over public safety scandals in which children have been the main victims. The ruling Communist party is worried that mass protests will threaten the country's social stability and considers them a serious challenge to its grip on power.

The government ordered the Huaqiang Battery Plant to shut about 10 days ago after local villagers approached the authorities with test results showing lead poisoning in some children, residents said.

"I hope the factory will be shut down forever, otherwise I am planning to move out," said a woman surnamed Yuan living about 550 yards (500 meters) from the factory. Her 11-year-old son tested positive for lead poisoning.

"I'm very worried about my child and hope the government can work out a plan to help the children expel the lead from their blood," she said.

Lead poisoning can damage the nervous and reproductive systems and cause high blood pressure and memory loss.

Control of hazardous chemicals is a chronic problem in China, where workshops and factories have sprung up all over the countryside. City officials usually have a vested interest in protecting local businesses, and public safety awareness is scant.

Decades of breakneck industrialization has left many areas polluted with chemicals and heavy metals where factories dumped waste and effluent with impunity.