More on recent incident in China:

BEIJING (Reuters) - Chinese police shot three villagers dead during an attack on a southern wind power plant by a crowd armed with spears, knives and Molotov cocktails, China's Xinhua news agency said.

It was the first official confirmation of deaths in what human rights group Amnesty International said was the first time Chinese police had fired on protesters since the crushing of the Tiananmen Square pro-democracy demonstrations in 1989.

Residents had said riot police had opened fire on Tuesday on protesters in the village of Dongzhoukeng in southern Guangdong province after they moved in to quell demonstrations over lack of compensation for land lost to the wind power plant.

Estimates from residents and rights groups put the number of dead between two and 20.

Xinhua said in an overnight report that villagers in Dongzhoukeng and Shigongliao attacked the plant on Monday and Tuesday last week.

"The first assault on December 5 (Monday) caused a seven-hour suspension of the plant's power generation," Xinhua said.

"In the second onslaught, over 170 armed villagers led by instigators...used knives, steel spears, sticks, dynamite powder, bottles filled with petroleum, and fishing detonators."

Police used tear gas to break up the protesters and arrested two, Xinhua said. The villagers then formed a blockade in a attempt to free their colleagues.

"(One of the villagers) shouted through a loudspeaker that they would throw detonators at the police and blow up the wind power plant if the police refused to retreat," Xinhua said.

"It became dark when the chaotic mob began to throw explosives at the police. Police were forced to open fire in alarm. In the chaos, three villagers died, eight were injured."

Xinhua quoted the Information Office of the city government of coastal Shanwei as saying that villagers had been incited to join in armed protests since June, using discontent over requisition of a coal-fired power plant in Dongzhoukeng as the excuse.

"They frequently formed armed protests in the construction ground of the coal-fired power plant, blocked public traffic, attacked government offices and even illegally detained people and vehicles passing through the village to threaten the local government to approve more compensation," it said.

"In order to magnify the effect of their protests, the instigators hatched the assault of the wind power plant in Shigongliao village, which had no relations with their former request for funds concerning the land requisition in Dongzhoukeng."

Investigations were still under way, Xinhua said.

China's Communist Party has a monopoly on power and brooks no dissent but protests are becoming increasingly common, sparked by disputes over land rights, corruption and a growing gap between rich and poor.

Many of the protests turn violent, but Amnesty said police opening fire marked an ugly turn.

"Police used guns on protesters the last time in 1989," said Chine Chan, East Asia Campaigner for Amnesty International, referring to China's crackdown on pro-democracy demonstrators by armed police and the People's Liberation Army.