SHANTOU, Guangdong - Protests over a planned power plant expansion in South China's Guangdong province ended Friday, the fourth day of protests, after government officials promised to release detained villagers.

About 500 villagers from the fishing township of Haimen in the city of Shantou gathered near an expressway toll gate at about 11:40 am, three days after villagers first gathered to protest the planned expansion of a coal-fired power plant by the Fengsheng Electricity Investment Company.

Villagers complained that the current power plant had led to a rise in the number of cancer patients, deterioration of the environment, and a drop in fishing hauls.

The government had said the project would be suspended.

But the protest turned violent and at least five people were detained by police on Wednesday for alleged vandalism.

Friday's crowd dispersed at about 6 pm after negotiations between government officials and three village representatives.

A village representative surnamed Lin told Xinhua that the government promised to release the detained villagers in accordance with the law as long as the crowd dispersed, but local officials also insisted they would punish any law offenders.

The officials also said they would hold talks with the family members of the detained villagers at the township government compound, Lin said.