Thousands of people have taken to the streets to protest over the construction of a heavy metal refinery in Shifang, Sichuan Province for environmental and health concerns, prompting authorities to halt the project and solicit public opinions, officials told the Global Times.

"Some people gathered outside the government building and began to throw bricks and water bottles at the building, government workers and police officers from 1:30 pm, resulting in some injuries to police officers," the local government said on its official Sina Weibo account on Monday evening.

"About half an hour later, armed police started to disperse the crowd with tear gas. Thirteen protesters were injured and were sent to the hospital in a timely fashion," it said.

A local police officer who demanded anonymity put the number of demonstrators at "several thousand" in an interview with the Global Times Monday.

Photos showing injured demonstrators and police beating protesters were circulated online, but their authenticity could not be immediately verified.

A local resident surnamed Feng claimed that there were still hundreds of residents gathered in a public square in the city center Monday night, watching an official publicity film elaborating on the safety of the project. No confrontations were reported.

Since Sunday evening, some local high school students and citizens began to gather outside the local government building to protest the construction of a molybdenum and copper refinery whose foundation had just been laid on Friday.

A local female resident surnamed Liu told the Global Times that locals are strongly against the project, believing that it would not bring economic development, but would harm people's well-being.

Some residents filed complaints with the local government demanding the project be scrapped. But officials did not resolve the issue properly in the past, residents said.

A post circulated on the Internet alleged that the pollution caused by the refinery would be even worse than the radiation damage caused by the Fukushima nuclear power plants during the earthquake in Japan in 2011.

Authorities called on residents not to follow or disseminate online rumors in a statement.

"The local government will definitely carry out supervision during the entire process of constructing the project. If the company fails in the environmental protection assessment, the local government would not allow it to go into production," Xu Guangyong, mayor of Shifang, told protesters Monday morning, the China News Service reported.

The local government also issued a statement ordering the company to stop construction from Monday, in a bid to calm protesters. Government work groups will collect ideas and proposals from people from all walks of life, officials said.

Also on Monday, local water supply, water quality inspection and food quarantine experts issued an open letter signed with their real names in an attempt to guarantee the safety of the project.