About 30 people in central China's Hubei province, including 16 children, have been diagnosed with excessive lead levels in their blood, local authorities and a victim said.

The suspected pollution source, Hubei Jitong Battery Co in an industrial park in Chongyang county, has been ordered to halt production, the county government said in a statement.

Two employees at the battery plant were first diagnosed with lead poisoning. This prompted more than ten residents living near the plant to be tested and later five employees and children were found with excessive lead levels.

The county government later arranged free tests for more residents near the plant and offered free treatment for residents found to be suffering from lead poisoning.

The investigation indicated that the work clothes employees brought home were the cause of the lead poisoning of their family members, the statement said.

The statement only gave the number of sickened children, but did not provide the total number of lead poisoning victims, including adults.

Gan Tiansheng, a former employee, said about 30 people have been found to be suffering from lead poisoning and 7 children and 13 adults were being cared for at a local hospital.

The remaining victims were under the care of doctors and being treated at home, he said.

Gan and his twin sons are among the victims. Gan said he worked at the plant for one year in 2008 before leaving due to suffering from stomach aches, fatigue and insomnia. He only learned the reason for the symptoms after a recent medical test found 689 micrograms of lead per liter of blood in his body.

Gan, however, blamed the plant's emitted gas and dust for his two-year-old sons' suffering, as they have never been to the battery manufacturing plant.

He added that the plant should be shut down permanently, as he worried that lead poisoning could affect his sons' growth.

Excessive amounts of lead in the body can harm the nervous and reproductive systems and cause high blood pressure and anemia. In severe cases, it can lead to convulsions, comas and even death.

The plant covers an area of 20,000 square meters and mainly produces batteries for cars, motorcycles and tricycles.