Police fired tear-gas and beat demonstrators who stormed government buildings in southern China on Tuesday to protest a power plant, witnesses said, in the latest violent unrest to hit the country.

Residents of Haimen, a town in the province of Guangdong, are demanding the coal-fired plant be moved, saying it is damaging their health, demonstrators told AFP by telephone.

They said a 15-year-old boy had been killed and more than 100 others badly beaten by riot police, although this could not be independently confirmed.

AFP calls to the local government in the town of Haimen went unanswered. A woman contacted by telephone at the local public security bureau denied there was unrest in the town.

Haimen is only around 115 kilometres (70 miles) northeast of Wukan village, where residents are in open revolt against the local government after what they say is years of illegal land grabs.

There is no indication that the protests are related, but they are part of an upsurge in social unrest in Guangdong, China's wealthiest province and the country's manufacturing hub.

China officials investigate couple with 8 babies
Beijing (AFP) Dec 20, 2011 - Authorities in China have launched an investigation after a couple broke family planning laws by having eight babies including several born illegally to surrogates, an official said Tuesday.

The wealthy couple in the southern province of Guangdong spent nearly one million yuan ($157,680) on in vitro fertilisation and two surrogate mothers, who gave birth to five of the babies, the Guangzhou Daily said.

State media did not identify the couple, but said they had "tried in vain for years" to get pregnant naturally and decided to hire surrogate mothers after successfully fertilising eight eggs.

The biological mother gave birth to three of the babies.

China's one-child policy generally limits couples to one offspring, with exceptions for certain groups. Surrogacy is illegal.

Couples who defy the one-child rule can face fines amounting to several years' salary, have access to social services cut and even go to prison. Their so-called "black children" have no legal status in China.

Authorities from the health department and other agencies are investigating the case, a spokeswoman for the Guangdong Provincial Family Planning Commission told AFP.

"This is not only a case of excessive births but it is about illegal surrogate pregnancies," the woman surnamed Gao said.

State media said the children were born in September and October of 2010 but family planning officials only found out this year when photographs of the eight babies were used in an advertisement.

The couple reportedly hired 11 nannies to care for the four boys and four girls.

Authorities were trying to find the couple and their children.

Zhang Feng, director of the Guangdong Provincial Family Planning Commission, said the birth of so many children and the use of surrogate mothers was "illegal" and "immoral", the Xinkuai Newspaper said.

Zhang said the medical institution involved should also be punished.