Cars were damaged but no one was injured during a riots in southern China's Guangzhou City on Saturday night after a pregnant woman from Sichuan Province was said to have been beaten up by local administrative officers because she had set up a stall in front of a supermarket without licence.

On Friday night, officers ordered the woman surnamed Wang, 20, and her husband surnamed Tang, 28, to leave because they were blocking the traffic, but a fight broke out and Wang, who was pregnant, fell to the ground, yesterday's Nanfang Daily reported.

A crowd gathered at the scene and some administrative vehicles were damaged while attempts were made to stop the ambulance taking Wang to hospital, according to the report.

More police officers arrived and 25 people were taken into custody.

The situation was temporarily settled early Saturday after Tang was quoted as saying his wife and their unborn baby were both well.

But a larger crowd gathered in the town on Saturday night, and more cars were damaged and traffic disrupted, China News Service reported.

The situation was controlled after "resolute measures" were taken by the police, according to the report. No more arrests were mentioned.

Some online posts claimed that the administrative officers were charging "protection fees" from unlicensed vendors and a fight had broken out when Wang and Tang refused to pay.

The police said that "a minority of people intentionally caused the trouble and damaged vehicles," and they would be punished under the law. No further details were released.

The local government said no one involved in the riot had been injured.