Thousands of people have rioted in Wengan county in southwest China's Guizhou province, accusing the police of a cover-up after the death of a local girl.

More than 10,000 people ransacked and torched government office buildings on Saturday, the Hong Kong-based Information Centre for Human Rights and Democracy said.

At least one person died and up to 150 people were injured in clashes with police, the organisation said. 

Nearly 200 rioters have been arrested.

The riots began after officials said that the 16-year-old committed suicide by jumping into a river.

However, many locals have suggested that she was raped and murdered. She was believed to have last been seen nine days ago with three men, two of them relatives of high-ranking government officials.

The violence escalated after the girl's uncle, who had protested against the conclusion of the police investigation, was reportedly beaten to death on Saturday.

Students 'beaten'

"As he was a teacher at the local high school, students from local schools went to the police to ask for justice, dozens of them I think, then some students were beaten by the police," an anonymous resident told the AFP news agency.

Police said that the girl committed suicide by throwing herself into a river [AFP]

Officials at the county government and police station did not answer telephone calls on Sunday, but the official Xinhua news agency said that the government is handling the situation "appropriately".

Several Chinese websites posting about the girl's death and the riots have been blocked, however a number were still accessible on Sunday.

With less than two months to go before the Beijing Olympics, China's government is working to quell any unrest and ensure order across the country.

The crackdown against protesters in Tibet in March drew international condemnation and caused several disruptions to the Olympic's torch's journey around the world.