(CNN) -- Authorities have restored order in a county in southern China after demonstrators burned a police station and government building, state-run news agencies reported.

Some of about 10,000 demonstrators overturned cars and set fires to protest the police investigation into the death of a teenage girl, according to the state-run China Daily and the privately owned Hong Kong Cable TV, a CNN affiliate.

It was the latest of several public demonstrations in China, and it came just weeks before China hosts the 2008 Summer Olympic Games in Beijing.

The riot started late Saturday afternoon and lasted until early Sunday morning in Weng'an County of Guizhou Province, the state-run Xinhua news agency reported.

Images broadcast on Hong Kong Cable TV showed several overturned cars in front of buildings in flames. The station identified the buildings as a police station and government building. The amateur video images were recorded by bloggers, the station said.

The unrest stemmed from the June 21 death of Li Shu Fan, 15, Hong Kong Cable TV reported. Police said the girl killed herself, and they released several suspects, according to the station.

The state-run China Daily newspaper attributed the rioters' anger to "officials' alleged attempt to cover up a murder case."

Armed police guarded the burned-out government buildings Sunday, according to Hong Kong Cable TV, and life appeared to be returning to normal after the latest of several recent public demonstrations.

The unrest comes as China prepares to welcome thousands of international visitors for the Olympic Games, which are scheduled to start August 8 in Beijing.

In March, thousands of anti-Chinese demonstrators rioted in the Tibetan capital, Lhasa. Estimates of the death toll ranged from 18 to 140. Rioters looted businesses and burned homes, stores and vehicles. Pro-Tibetan demonstrators also dogged the Olympic torch relay in several cities around the world.

In addition, many parents complained about shoddy construction and threatened to sue the government after several schools collapsed during a devastating earthquake that struck southwestern China on May 12.

All About China • Summer Olympics • Tibet