The riot on Monday night in Guiyang, the capital of Guizhou province, highlights tensions over China's tens of millions of migrant workers who have left the countryside to look for work in cities, often settling in urban areas in violation of strict household registration rules.
Witnesses said the migrant, identified only by his surname, Guo, was stopped in a park by people hired by police to check identity papers, according to the state-run Guizhou Metropolitan News. Such civilian forces who assist police are common in Chinese cities, according to the AP.
Guo didn't have a permit to live in the city and refused to pay for one, the report said Wednesday. It said he was found shortly after, bleeding from a severe head wound.
Police officers rushed to the scene and asked that Guo be sent to the hospital before going to a police station for questioning with the civilian workers, the paper said.
Guiyang police refused to confirm the report on Thursday, saying the details had not been given official approval.