The Information Center for Human Rights and Democracy said thousands of Zhuang people fought with hundreds of Han Chinese from the Shandong Xinfa Aluminium Co. whose mining activities were said to have polluted sources of drinking water in the province's Jinxi County.

Violence erupted over road construction Sunday when hundreds of Han workers attacked the Zhuang villagers with wooden sticks. The villagers fought back with makeshift weapons in the following days, smashing the company office and damaging cars including police and military vehicles, the center said.

It said the Jinxi County government confirmed the unrest but denied reports that three workers died.

More than 1,000 antiriot police officers were deployed to keep the peace but thousands of villagers, some of them returning to the villages from nearby cities, have continued to protest, according to the Boxun news website, which frequently posts reports on human rights in China.

A staff at the Guangxi government office told Kyodo News that only about five people were injured and the crowd has dispersed, before hanging up the phone.

Photographs from mainland websites showed police in riot gear standing guard in Jinxi and villagers holding up banners calling for Shandong Xinfa to ''return to Jinxi our clean river.''

Zhuang is the most populous ethnic minority group in China with 17 million people living mainly in Guangxi and nearby provinces including Guangdong, Yunnan, Guizhou and Hunan, according to government figures.

==Kyodo