An American-owned battery plant in China will remain shut until the end of the year over fears it has caused lead poisoning in local children, the Shanghai Daily reported on Friday.
The factory, run by US Fortune 500 company Johnson Controls, was one of two plants closed down temporarily last week by Shanghai authorities after tests on local children found some had excessive lead in their blood.
At the time, the government gave no time frame, but the Shanghai Daily said the plant would remain closed for three months.
The number of children living near the plants with excessive lead levels had risen to 32 from 25 last week, following the testing of more than 1,100 children, the paper quoted officials as saying.
Of the 32 children found to have high lead levels, 15 had been hospitalised, the report said.
The Shanghai Environmental Protection Bureau said last week an initial investigation found that the factory had been emitting dust and smoke containing lead.
The second plant, called Shanghai Xinmingyuan Auto Accessories Co., had been found using lead in production without proper approval, it added.
A Shanghai-based spokeswoman for the company could not be reached for comment Friday.
New York-listed Johnson Controls has previously said it does not believe its plant was the source of the problem.
Excessive levels of lead in the blood are considered hazardous, particularly to children, who can experience stunted growth and mental retardation.
China's rapid industrialisation over the past 30 years has enabled it to become the world's number-two economy, but has also left it with widespread environmental damage that has triggered numerous public health scares.
Earlier this year, authorities in the eastern province of Zhejiang detained 74 people and suspended work at hundreds of factories after 172 people -- including 53 children -- fell ill due to lead poisoning.
In 2009, local smelting plants were found responsible for nearly 1,000 children testing positive for lead poisoning in the central province of Henan.