Police on Friday fired tear gas at hundreds of people and detained a team of Hong Kong journalists in a southern Chinese town that was the scene of violent protests earlier this week.

Television footage from Hong Kong broadcaster Cable TV showed police in full riot gear fire gas cannisters towards a crowd of residents gathered on a main highway, who covered their faces and fled.

China's state-run Xinhua news agency said around 500 people gathered on a highway for a fourth day of protests against the planned expansion of a coal-fired plant in the southern town of Haimen in Guangdong province.

The crowd dispersed early Friday evening, according to Xinhua, after talks between government officials and village representatives.

Cable TV said plainclothes police had earlier detained three of its staff as they reported from the town and held them for six hours before ordering them to leave.

A police spokeswoman contacted by telephone in Haimen said she was unaware of the incident.

Residents contacted by telephone told AFP police had fired tear gas several times on Friday, including at students who gathered outside a police station to demand the release of protesters detained earlier in the week. Xinhua has said five people were detained over vandalism.

But there was no evidence of the large-scale protests seen on Tuesday and Wednesday, when thousands of people took to the streets, leading to violent clashes between demonstrators and police.

Some residents said a 15-year-old boy and a middle-aged woman had been killed in Tuesday's violence, but a local official quoted by Xinhua denied anyone had died.

Residents of the coastal town say harmful pollution from the power plant has caused a rise in cancer cases and a drop in in fishing hauls.

After Tuesday's protests, the local government announced that the plant's expansion would be suspended pending a review by higher authorities.

But residents contacted by AFP on Wednesday and Thursday were either unaware of the decision or doubted the government's sincerity.

Haimen residents told AFP by telephone on Friday they wanted foreign journalists to go to the town, after a protest in the nearby village of Wukan attracted worldwide media attention.

Several said there were tens of thousands of protesters on the streets on Friday, but television footage and photographs from the scene showed much smaller numbers.

The villagers of Wukan ended their long stand-off with authorities on Tuesday after a senior provincial official pledged to free three detained protest leaders and investigate their grievances.