"The villagers will not give up if there is no concrete action to move the factories away," said a Mr. Lu, a villager who said he had witnessed part of the confrontation. "The crowd is growing. There are at least 50,000 or 60,000 people." He would not give his full name.

Other villagers gave substantially smaller crowd estimates. But they agreed on the broad outlines of a clash that came after villagers say they had tried in vain for two years to curb pollution from chemical plants in a nearby industrial park.

An account in a local state-controlled newspaper blamed local agitators for the brawl and said thousands of people had set upon government workers with rocks and clubs.

There were conflicting reports about injuries, and Mr. Lu said two elderly women among the protesters had been gravely injured after being run over by a police vehicle. The article in The Dongyang Daily said more than 30 government employees had been hospitalized, including 5 with serious injuries. Neither account could be confirmed.

A reporter for an English-language newspaper in Hong Kong, The South China Morning Post, visited the riot scene and described overturned buses and shattered cars, adding that "a police uniform is draped over one car - a trophy." The reporter, whose account was published on Wednesday, was detained by the police after leaving the village and released after her notes were confiscated.

Several thousand people in Beijing and Guangzhou protested against Japan last weekend as well. By contrast, those protests were officially authorized, as young urbanites shouted slogans and tossed bottles at the Japanese Embassy at a time of heightened diplomatic tensions between the countries.

But the riot described in Huaxi is more a symptom of the widening social unrest in the Chinese countryside that has become a serious concern for top leaders. Last year, tens of thousands of protesters in western Sichuan Province clashed with the police over a dam project. Smaller rural protests are commonplace and often violent.

Huaxi is a few hours' drive south of Hangzhou, the provincial capital of coastal Zhejiang. It is a short distance from the Zhuxi Industrial Function Zone, the local industrial park that villagers say is home to 13 chemical factories.

"The air stinks from the factories," said a villager, Wang Yuehe. She said the local river was filled with pollutants that had contaminated local farmland. "We can't grow our crops. The factories had promised to do a good environmental job, but they have done almost nothing."

Ms. Wang said villagers had pooled their money for two years and sent representatives to file complaints at government petition offices in Zhejiang Province and in Beijing. "But there have been no results so far," she said.

On March 24 a group of elderly people, mostly women, set up roadblocks on the road leading to the factories. On April 2 the government temporarily shut down the factories. But by Sunday local officials had dispatched police officers and workers to break up the protest. Villagers said as many as 3,000 officers had arrived in scores of cars and buses.

The fight apparently erupted after officers had already taken down the tent city. Villagers said thousands of people had hurried to the scene after the police attacked some of the protesters. The mob then surrounded workers and officers, said witnesses and the newspaper account.

Some local officials who had retreated to a nearby school were reported to have been attacked when they tried to leave on foot. "I saw over 10 bodies on the ground, both officials and villagers," Mr. Lu said.

Several villagers said local officials owned shares in various local factories. But according to the article in the official newspaper, local officials "paid great attention" to the environmental problems and had paid compensation for past discharges of pollutants into the river.

The article also said that officials decided to break up the protests on Sunday because they were worried that "the coming of cold air and dramatic temperature drops threatened the health of feeble old women."

Copyright 2005 The New York Times Company