Authorities in a Chinese city ordered the immediate shutdown of a chemical plant on Sunday as thousands of protesters took to the streets demanding the factory be moved over pollution fears. The demonstration by some 12,000 residents in the northeastern city of Dalian is the latest bout of unrest to hit China as anger over issues such as social inequalities and environmental degradation boils over. Residents in the port city in Liaoning province gathered in front of the municipal government's office on Sunday morning, and were joined by more and more people, the official Xinhua news agency said. Some scuffled with riot police, throwing bottles of water at them as they tried to cordon off one of the city's main arteries, but there were no reports of injuries, it added. Hundreds of people then broke off and started moving to other parts of the city, chanting slogans and waving banners. According to unconfirmed postings on Twitter, a lot of armed police vehicles were seen moving into the city.