Violence erupted on Sunday after more than 10,000 people took to the streets in southern China to oppose government plans to construct an incinerator.
Witnesses said at least 3,000 police officers were in Lubu township as protesters from the surrounding villages demonstrated in Lubu's main street for about six hours, calling for authorities to scrap the construction plans amid fears that the incinerator, which would generate power and dispose garbage in the region, would contaminate the nearby Xi River, the area's main water source.
Footage posted on social media showed police, which included paramilitary police and SWAT teams, attempting to contain the protest.
Several officers were recorded using their batons to hit protesters crouching on the ground or against the wall.
One witness told the BBC that one police officer was seriously injured while two civilians suffered head injuries.
According to residents, the confrontation took place at around noon in fields across Lubu's government offices.
In a post on social media, the Communist Party propaganda department for the district wrote that "some ordinary people who are unaware of the truth led by some troublemakers attempted to storm the Lubu town government."
It said that those who had attacked police officers should surrender themselves, while people inside the government offices should leave immediately.
More than 70,000 people live in Lubu, which is in Guangdong Province. A resident told the BBC that further protests are planned for Monday, but will not be as well attended because many people work outside the town.
"We were in a stand-off with the police for a long time. But then some small-scale conflicts broke out and people become very emotional," one protester told the South China Morning Post.
"We oppose the incinerator because it will contaminate the Xi River. Lubu is upstream and many people downstream drink its water."
On Saturday, government officials ordered construction of the incinerator to stop after 1,000 villagers protested in June. No reason was given for the delay, leaving residents worried that it would only be a temporary measure.