Another official resigned from his post over the incident that took place in May in Jiangxi province's Fuzhou city, killing four people -- including the alleged perpetrator -- and injuring 10 others.

Xi Dongsen, former head of a Fuzhou district where the blasts went off, was dismissed from his post and placed on probation within the Communist Party for two years, the official Xinhua news agency reported.

Probation is the second-most serious punishment after expulsion from the party.

He Daxin, former president of a Fuzhou court, was given a serious warning from the party and his request to resign from his post was accepted by city authorities, it added.

A spokesman for the provincial discipline inspection committee -- a body charged with rooting out malfeasance among party officials -- confirmed the Xinhua information when contacted by AFP, but refused further comment.

The report said another 14 officials were also disciplined, but did not detail the nature of their punishments.

The explosions struck at 10-minute intervals on the morning of May 26 at the parking garage of the city prosecutor's office, at a district government office and near the city's food and drug agency.

Qian Mingqi, the 52-year-old suspect who allegedly set them off, had been involved in a long-standing land dispute with the local government -- a common trigger for unrest in China.

According to Xinhua, Qian had been resettled to make way for a highway in 2002, but was unhappy at the compensation offered to him.

The report said the officials failed to properly deal with the "reasonable and legitimate requests" of local residents.

The unusually premeditated incident made waves around China, where bomb attacks -- while still rare -- have been increasingly frequent in recent years.

They have typically been carried out by individuals angry over perceived injustices, business disputes or other pressures associated with China's rapid modernisation.

In another such incident in May, more than 40 people were injured when a disgruntled former employee set off a petrol bomb at a bank in northwest China.

"A small amount of children living in the Kangqiao area in eastern Shanghai were found to have excessive levels of lead in their blood in early September," the Shanghai Environmental Protection Bureau said in a statement.

The agency said an initial investigation found that battery maker Shanghai Johnson Controls International Battery Co. -- a unit of the New York-listed Johnson Controls -- had been emitting dust and smoke containing lead.

Another plant called Shanghai Xinmingyuan Auto Accessories Co. had been found using lead in production without proper approval, and both factories had subsequently been ordered to shut down, it added.

Johnson Controls, an industrial giant that ranked 76th on this year's Fortune 500 list, said it believed its plant was not the source of the problem but that it was cooperating with the city government.

"We are working with the government to understand and address these issues. However, we have no reason to believe we are the source of the issue," it said in a statement to AFP.

Johnson Controls said the plant's lead emission average was one-seventh of China's national standard, while the discharge through wastewater was one-tenth the national requirement.

Xinmingyuan Auto Accessories refused to comment.

Excessive levels of lead in the blood are considered hazardous, particularly to children, who can experience stunted growth and mental retardation.

The environmental bureau did not say how many children were affected by the pollution leak but the Shanghai Daily, a newspaper controlled by the local government, said that 25 children in the area were found with high lead levels.

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.

And in 2009, local smelting plants were found responsible for nearly 1,000 children testing positive for lead poisoning in the central province of Henan.