Angry rioters attacked the office of the local unit of the Communist Party and set fire to government buildings and vehicles after news spread that a man was killed in police custody.

The person killed in Wengan county of southwestern China?s Guizhou province was the uncle of a girl, who had been allegedly raped and killed a few days earlier. The mob demanded justice saying the police was trying to protect the son of a local politician suspected of killing the girl.

The girl?s uncle died after police beat him for protesting against shoddy investigation into the case concerning his niece, reports in Chinese blogs and anonymously run web sites said. The publication of this news in these internet sites forced the official Xinhua news agency to circulate a cautious version of it.

The government seemed very careful to make sure the protest does not spread because a large part of the mob comprised of students of the killed man, who happened to be a teacher in a local school. The government is particularly worried that the protest would give rise to other demonstrations in other parts of China on the eve of the Olympic Games, sources said.

Police cover-up

This is the most serious case of public anger to come to the surface since the protests by parents of children killed in collapsed school buildings in the May 12 earthquake in Sichuan. The government has since ordered an investigation into the construction quality of school buildings in Sichuan.

The violent protests began in Wengan county on Saturday and continued till Sunday afternoon with hundreds of people involved in demonstrations outside the local police station and Communist Party office besides smashing glass panes of government buildings.

Xinhua news agency said that the mob was instigated by ?some people who did not know about the exact context of what had happened? with regard to the investigation. The uncle was protesting against what he regarded as a cover-up by the police, which claimed that his 15-year old niece had committed suicide on June 20, reports suggest. Internet postings suggest that the police was trying to protect a suspect, who happened to be the son of a local politician.

A large contingent of police and paramilitary police vehicles and personnel has reached Wengan from surrounding areas, sources said. The girl?s family was holding on the body of the deceased girl and refusing to hand it over to officials, who were trying to persuade the family members, sources said.