After three days of protests by thousands of citizens over pollution fears, a local Chinese government relented and agreed that a petrochemical factory would not be expanded, only to see the protests persist.

The standoff in the prosperous city of Ningbo has highlighted the deep mistrust between people and the government in China. Should they last longer, the demonstrations would upset an atmosphere of calm that Chinese leaders want for a transfer of power in the Communist Party leadership next month.

The protest, which started sporadically last week, swelled over the weekend and led to clashes between citizens and police. The Ningbo city government announced Sunday evening that they and the project's investor — the state-owned petrochemical behemoth Sinopec — had "resolutely" agreed not to go ahead with the expansion.

Outside the government offices where crowds of protesters stayed, an official tried to read the statement on a loudspeaker but was drowned out by shouts demanding the mayor step down. On the third attempt, the crowd briefly cheered but then turned back to demanding that authorities release protesters detained earlier and believed to be held inside. Though the crowd dissipated late Sunday, about 200 people returned again Monday morning.

"There is very little public confidence in the government," 24-year-old protester Liu Li said Sunday. "Who knows if they are saying this just to make us leave and then keep on doing the project."

Protesters returned again Monday morning, though the crowd was smaller, about 200 people, and was comprised mainly of older people. Police channeled the protesters away from the front of the modest government building off to a side street, and plainclothes officers mingled in the crowd.

The city government was likely under great pressure to defuse the protest with China's leadership wanting calm for the party congress that starts Nov. 8. It was unclear whether local authorities will ultimately cancel the petrochemical project or continue it when the pressure is lower.

Hundreds of people outside the government offices refused to budge despite being urged to leave by officials. Riot police with helmets and shields came out of the government compound and pushed the crowd back. Some people including families ran away. Police dragged six men and one woman into the compound, beating and kicking at least three of them. Police also smashed placards and took away flags.

The crowd roared for the protesters' release. Police also briefly detained a correspondent from the British television network ITN.

The demonstration in wealthy Zhejiang province is the latest this year over fears of health risks and declining property values from industrial projects, as Chinese who have seen their living standards improve become more outspoken against environmentally risky projects in their areas. A senior adviser to the Environment Ministry told legislators on Friday that the number of protests over environmental issues has increased nearly 30 percent a year for the past 15 years and that they had been getting larger, according to state media.

"The government hides information from the people. They are only interested in scoring political points and making money," said one protester, Luo Luan. "They don't care about destroying the environment or damaging people's lives."

The protests began a few days earlier in the coastal district of Zhenhai, site of the Sinopec Zhenhai Refining & Chemical Co. factory, which state media has described as an $8.9 billion complex to produce oil and ethylene. On Saturday they swelled and spread to the center of Ningbo city, whose officials oversee Zhenhai.

Residents reported that Saturday's protests involved thousands of people and turned violent after authorities used tear gas and arrested participants.

Authorities said "a few" people disrupted public order by staging sit-ins, unfurling banners, distributing fliers and obstructing roads.

Early Sunday, thousands of residents began gathering outside the offices of the municipal government. Hundreds marched away from the offices in an apparent effort to round up more support along nearby shopping streets. Police diverted traffic to allow them to pass down a main road.

The crowds in Ningbo are a slice of China's rising middle class that poses an increasingly boisterous challenge to the country's incoming leadership: Armed with expensive smartphones, Internet connectivity and higher expectations than the generations before them, their impatience with the government's customary lack of response is palpable.

A 30-year-old woman surnamed Wang said officers took her to a police station Saturday and made her sign a guarantee that she would not participate in any more protests, but she came back Sunday anyway.

"They won't even let us sing the national anthem," Wang said. "They kept asking me who the leader of the protests was and I said that this is all voluntary. We have no leader."

In a sign that censors were at work, the name "Zhenhai" was blocked on China's popular microblogging site Sina Weibo.

Protester Yu Yibing said he wanted the factory to be closed and his 7-year-old son to grow up in a clean environment.

"As the common people, we need to live in a green environment. This is a reasonable request," Yu said. "But the government only puts out some statement and refuses to see us and also suppresses us. I don't know how else we can express our views."

The Zhenhai district government said in a short statement on its website Sunday evening that the project wouldn't go ahead and that refining at the factory would stop for the time being while a scientific review is conducted.

Past environmental protests have targeted a waste-water pipeline in eastern China and a copper plant in west-central China. A week ago, hundreds protested for several days in a small town on China's Hainan island over a coal-fired power plant.