Local reports and residents in southern China say a riot broke out after a dispute at a bridge toll booth in the southern province of Guangdong.
By Francis Markus
At least 17 people were reported to have been detained.
The incident last week was the latest in a series of unrelated riots in various parts of the country.
It is not clear if the frequency of such protests is increasing, or whether it is simply that more information is emerging about them.
The latest incident, near the southern town of Jieyang, started after a woman was beaten up by staff at a bridge toll-booth after complaining she had been overcharged.
Residents said 1,000 police were deployed after local people set fire to the toll-booth and a fire engine sent to the scene accidentally ran over and killed a teenager.
In the last few weeks, there have been several such incidents in China.
At least seven people have been killed in clashes between Chinese Muslims and other villagers, sparked by a traffic accident.
Elsewhere, tens of thousands of people protested after the beating of a migrant worker allegedly by a government official. And similar numbers stormed a government complex over what they said was inadequate compensation for being displaced by a dam project.
These incidents are too fragmented to form a challenge to the Communist Party's rule.
But some of them do highlight people's frustration at being unable to resolve grievances against local authorities by other means.
There is talk about how to reform the hopelessly ineffectual system by which people can submit petitions to outline their complaints.
But even that may not help ease many clashes between ordinary people and local officials, who often use their power to protect their own economic interests.