Beijing — Rioters in southwestern China torched government buildings and cars during the weekend after anger over a suspected cover-up by police of a schoolgirl’s rape and murder exploded into violent protests.

Three state buildings were ransacked after the 15-year-old girl’s uncle died following an alleged beating by police. The official Xinhua news agency said only that riots had erupted due to “dissatisfaction” over the investigation.

Pictures posted on internet blogs showed several thousand people gathered in front of the Wengan county police station, its windows shattered and the building smouldering.

The Hong Kong-based Information Center for Human Rights and Democracy said that more than 10,000 people took to the streets in the protests, with up to 150 people injured in clashes.

Police have arrested nearly 200 rioters and were seeking to round up others. Over 1,500 paramilitary and riot police were reported to have been sent to the region.

Locals said that the protests began after the girl’s uncle, a school teacher, was pronounced dead on Saturday afternoon. The uncle had protested against the police’s conclusion that his niece committed suicide.

Internet postings said that the girl had been raped and then killed nine days ago and that the police were trying to protect the suspect, who was identified as the son of a local politician.