It is the latest explosive example of how political corruption in China can have a dangerously destabilising impact. Thousands of rioters torched police cars and government office buildings in the south-western province of Guizhou after allegations that local officials covered up a teenage girl's death.
It started with the rape and murder of a 15-year-old girl. The story that flashed around Weng'an county was that three men were responsible, two of them with great "guangxi", or local connections. One of them was reportedly the son of the deputy mayor. When the police report said she had killed herself, tensions really began to simmer. When her popular schoolteacher uncle went to the police to seek justice, he was beaten into a coma and subsequently died. The tensions turned into rioting.
Lacking formal means to vent their anger, the people of Weng'an turned the town upside down, and the YouTube website carried shocking pictures of burning police cars and local government offices.
The scenes of mayhem and anarchy are the ones the Communist Party fears most as it is always worried that dissent could spread nationwide. Corruption at local level is something the Chinese government has vowed to wipe out, and last week it introduced a five-year plan to combat it.
Eyewitnesses reported one death and many injuries in the riots. At around 4am yesterday morning, police used megaphones to urge people to leave the area, and local television stations broadcast notices asking people who participated in the protest to turn themselves in. The riots even made it on to the official Xinhua news agency, which ran a brief story and blamed the riots on unhappiness about the official ruling over the girl's death.
"Some people who did not know about the exact context of what had happened were instigated to mob the police station and the office buildings of the county government and Communist Party committee," it said, without giving details of what the official finding was or the cause of death. It said that order had been restored.
According to the Hong Kong-based Information Centre for Human Rights and Democracy, more than 10,000 people took to the streets in the protests, with up to 150 people injured in clashes with police. The local Communist Party HQ was badly damaged.
Another 1,500 paramilitary and riot police had been deployed to the county and police arrested nearly 200 rioters. Yesterday, they were using the video footage posted online to round up others caught ransacking the three government and police buildings.
Public dissent of any kind is not tolerated in China. After the 12 May earthquake, parents of children who died in shoddily built schools were arrested when they tried to protest against official corruption which led to the bad building practice in the schools where their offspring had perished.
Xinhua said the Guizhou government has taken measures to "appropriately" handle the situation.
The internet was abuzz with stories of the girl's plight, and the state crackdown on the rioters. Opening the sites was difficult as the Great Firewall of China descended to make it difficult to open them. The timing of the riots is bad for President Hu Jintao's government.
Anti-Chinese riots in Tibet in March prompted a tough response by the Chinese authorities, earning Beijing international condemnation. However, a lot of international goodwill was restored by the relatively open response to the Sichuan earthquake, allowing foreign donations into the country.
The country is trying to present a stable and harmonious image ahead of the Beijing Olympic Games in August. A local official said the girl's family had rejected the authorities' offer of 3,000 yuan (£220) compensation, later increased to 30,000 yuan (£2,200), and residents had donated money to the family to sue local authorities.