Demonstrations over a power plant in southern China turned violent for a second straight day on Wednesday when police fired tear-gas and beat protesters, witnesses said.

At least six people were said to have been injured in the clashes with police in Haimen, a town in Guangdong province where residents are protesting against a coal-fired power plant that they say is a health hazard.

Photographs posted online purportedly of protests in Haimen showed an overturned police car.

The latest violence came after witnesses told AFP on Tuesday that a 15-year-old boy and a middle-aged woman had been killed in the clashes with police, although this could not immediately be confirmed.

Oriental TV, a Hong Kong-based television station, said six residents had died and nearly 200 were injured in Tuesday's violent confrontation, which led local authorities to announce the suspension of a plan to expand the plant.

Protesters contacted by telephone on Wednesday said they were either unaware of the suspension or sceptical about the government's intentions.

"At least 200 riot police rushed in and beat anyone they met and at least six people were injured," a protester, who refused to be named, told AFP by telephone from a service station where demonstrators had gathered.

"We won't stop demonstrating because the government is playing a word game with us -- they said they would suspend the project but not totally stop it, so we won't give up."

Another resident said the local government had not yet contacted the protesters.

"None of the leaders have showed up so far, not even on TV," the resident told AFP by telephone. "We want them to solve this problem, we can't bear the pollution any more."

Another resident surnamed Zheng said several thousand protesters attempting to block a highway into Haimen clashed with police when relatives of four people detained during Tuesday's unrest demanded their loved ones be released.

State media reported last month that a 7.4-billion-yuan ($1.17-billion) expansion of the power plant had failed environmental tests and toxic metals found in local waterways "exceeded the standard level".

Online searches for Haimen were blocked on Wednesday, as authorities tried to keep news of the clashes from spreading.

Haimen is only around 115 kilometres (70 miles) northeast of Wukan village, where residents have been 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 strives to defuse unrest in wealthy south
Wukan, China (AFP) Dec 21, 2011 - Authorities in southern China moved Wednesday to defuse outbreaks of unrest, agreeing to free villagers detained for protesting land seizures and suspending a power plant project.

The wealthy province of Guangdong has seen an upsurge in protests in recent months, as middle-class Chinese become increasingly willing to take on the government on issues ranging from official corruption to pollution.

On Wednesday, a senior provincial official held talks with representatives of Wukan, a fishing village that has become a thorn in the government's side, to try to persuade them to end an embarrassing stand-off with authorities.

Deputy provincial party secretary Zhu Mingguo agreed to free three village leaders detained on December 9 and to release the body of a fourth who died in police custody to his relatives, village spokesman Lin Zulian said.

A police blockade that had surrounded the village since the men were arrested has now been removed and a 10-member government team will go to Wukan to investigate the villagers' complaints.

"I'm very satisfied with the outcome of the meeting," Lin said. "This is not a victory, but it is a beginning."

The decision to send a senior provincial official to deal with the dispute is an indication of how concerned the Guangdong government was by the rare revolt in Wukan.

It came as demonstrations over a coal-fired power plant in the town of Haimen, also in Guangdong, turned violent for a second straight day on Wednesday when police fired tear-gas and beat protesters, witnesses said.

Haimen is only around 115 kilometres (70 miles) northeast of Wukan, and while there is no indication that the events are related, they are evidence of the rising challenge posed by social unrest.

Neither protest has received much coverage in China's state-run media, but Guangdong's proximity to neighbouring Hong Kong, with its independent media, means that news of both has got out, apparently worrying authorities.

Officials overseeing Haimen said in a statement late Tuesday they would suspend the power station project and refer the case to "supervisory authorities".

But protesters contacted by telephone on Wednesday said they were either unaware of the suspension or sceptical about the government's intentions.

The latest violence came after witnesses told AFP on Tuesday that a 15-year-old boy and a middle-aged woman had been killed in the clashes with police, although this could not immediately be confirmed.

Oriental TV, a Hong Kong-based television station, said six residents had died and nearly 200 were injured in the confrontation.

Online searches for Haimen were blocked in China on Wednesday, as authorities tried to keep news of the clashes from spreading, but one resident said they planned to continue their demonstrations.

"We won't stop demonstrating because the government is playing a word game with us -- they said they would suspend the project but not totally stop it, so we won't give up," he told AFP by telephone.

State media reported last month that a 7.4-billion-yuan ($1.17-billion) expansion of the power plant had failed environmental tests and toxic metals found in local waterways "exceeded the standard level".

Three decades of rapid economic growth have left many waterways in China severely contaminated and protests over environmental pollution are increasing -- particularly in the south, where most of China's factories are located.

Protests over land seizures are relatively common, but the stand taken by the villagers of Wukan -- who drove out local Communist leaders and have effectively been governing themselves since September -- was unusual.

Villagers' anger boiled over with the death in police custody on December 11 of Xue Jinbo, a community leader who they suspect was beaten to death. The government has said he suffered a heart attack.

Spokesman Lin said after the talks with Zhu that the issue of stolen land -- which villagers say had been going on for years and has deprived many farmers of their livelihood -- had yet to be resolved.

Nonetheless, there was a mood of relief in Wukan, where around 1,000 villagers gathered for a rally and food supplies -- which had begun to run low -- reached the village.

"We have struggled and got the attention of the provincial and central governments. But we paid a heavy price with the loss of our beloved Xue Jinbo's life," Yang Semao told a packed village square.

"There is the light of a new dawn, a new day. But we must be careful because the dark clouds can easily return."

Many villagers had long maintained that they remained loyal to China's ruling Communist party, and blamed their problems on a small group of corrupt local officials.

"There was so much pressure on us, people have been so afraid," a villager surnamed Zhuang told AFP. "When I heard that he (Zhu) was coming, I felt that a great weight was lifted off my heart."