The protests began on Thursday, when as many as 500 people stormed a compound owned by the New York-listed Jinko Solar Holding Co, official news agency Xinhua reported on Sunday.
Protesters overturned vehicles before being dispersed, but they continued to camp outside the factory until the riot police with helmets, vests, batons and shields arrived late on Sunday.
Toxic waste from the factory, which manufactures photovoltaic panels, cells and wafers, killed large numbers of fish in a nearby river, and authorities had already ordered the company to suspend operations, the news agency said.
Protesters put up banners with the slogan "Return our lives to us, stay away from Jinko," according to photographs published on the website of the National Business Daily newspaper (
www.nbd.com.cn) on Sunday.
An elderly woman who did not want to give her name complained bitterly about the local government's tactics.
"The factory has been polluting us all this while and now that we make some noise, the government shuts us up. They are all in this together, now we just have to die here silently. You can see all these riot police here, we are just helpless villagers."