Beijing (CNN) -- Bowing to intense pressure from local residents, authorities in an eastern Chinese city abandoned plans to build a controversial sewage pipeline for a paper mill, the local government announced Saturday.
After days of fuming at potential water pollution caused by the project and defying official orders, thousands of residents in Qidong city north of Shanghai gathered in a downtown square early Saturday morning to voice their opposition to the project, a witness told CNN.
Blocked by hundreds of awaiting police, the protesters marched to the city government building, said the witness, who asked to be identified only by his surname Wan for fear of official reprisal.
"Most people stayed calm," Wan said. "Only a few clashed with police, but there were no serious injuries."
Photos posted on Chinese social media sites show an angry crowd storming the government compound, ransacking offices and overturning cars.
Residents in Qidong have said the proposed 110-kilometer (70-mile) pipeline would eventually release 150,000 tons of sewage into the sea nearby every day, contaminating a major fishing harbor and local water supply.
Oji Paper, the mill's Japanese parent company, denied its discharge would cause pollution.
"Our factory has very strict water quality management system based on national standards," the company said in a statement. "We only release sewage after it is purified in house to meet such standards."
State-run media earlier reported that local authorities had requested residents not to take to the streets but have remained largely silent on the protest. Internet censors began deleting posts and images on the topic Saturday afternoon, as the central government continues to tighten its grip on social media ahead of a sensitive Communist Party meeting later this year that will see a once-in-a-decade leadership transition.
Although most Chinese internet users appeared to hail the protest a success, many also cautioned the demonstrators to avoid violence that could prompt future retribution from the authorities.
The protest in Qidong is the latest example of China's increasingly Internet-savvy urban residents -- long considered the main beneficiaries of the government's economic reforms -- banding together for a common cause, especially environmental issues.
Chinese officials in southwestern Sichuan province scrapped plans early this month to build a $1.6 billion heavy metals plant following violent protests by local residents worried about the project's environmental impact.
Last August, a large protest prompted authorities in the northeastern port city of Dalian to shut down a controversial chemical plant that produced paraxylene (PX), an allegedly carcinogenic compound used in the production of polyester films and fabrics.
In 2008, residents in Shanghai worried about radiation risks took to the streets to protest the construction of a high-speed rail line using the magnetic levitation technology, forcing the government to suspend the project indefinitely. And in 2007, residents in the southeastern city of Xiamen marched against a local PX plant, which eventually moved out of town.
CNN's C.Y. Xu contributed to this report.