Chinese authorities have scrapped a plan to build a copper plant in a central city after residents staged several days of protests against the prospect of heavy pollution from the factory.

Thousands of residents of Shifang city in Sichuan province had taken to the streets in the past three days to protest the refinery, complaining that factory emissions would poison them.

In a statement posted on its website Tuesday, the government of Shifang says it has stopped the metal plant project, handing an unexpected victory to the residents.

Police in Shifang also released 21 of the 27 people detained for participating in the protests after they “repented for their mistakes.” Six people remain in custody and could face charges for their involvement in the unrest.

At least 13 people were injured in the protests, which saw riot police fire tear gas and beat demonstrators with batons to disperse the crowds.

Localized protests have become increasingly common in China, where officials have provoked public anger by pursuing rapid urban development, often at the expense of the environment.

In August 2011, thousands of protesters worried about pollution forced authorities to close a chemical plant in the northeastern city of Dalian.

Chinese state media said Wednesday that the Shifang incident should serve as a “grave warning” to local governments. The Communist Party-run Global Times said the Shifang government's credibility was damaged because of “serious loopholes” in the decision-making process, saying the whole project was carried out “hastily.”