JOHANNESBURG: Angry crowds of protesters surrounded a police station in a South African industrial town Tuesday as bloody riots threatened to turn deadly, police said.

"We ourselves are under attack at Zamdela police station," a nervous female police officer said by telephone.

"The mob is now attacking. They are surrounding the building. They're trying to break in," she told AFP in a shaky voice. The officer refused to give her name.

Police fired rubber bullets and water cannon to disperse thousands of protestors in Zamdela, a shantytown next to the industrial town of Sasolburg some 85 kilometres (50 miles) south of Johannesburg, the Mail and Guardian newspaper reported.

Zamdela residents have been protesting since Sunday against the town's incorporation into a neighbouring municipality.

The crowds started fires, blocked roads and looted shops, local media reported.

On Tuesday protesters turned on journalists, and a French photographer was hit on the head with rocks.

"We were driving out of the informal settlement ... and a group of about 20 (to) 40 guys turned on the car and started pelting it with rocks," said Alon Skuy, photographer with The Times newspaper.

"We drove through to try to escape. All the windows were broken. In the process (the photographer) was hit in the head. She went immediately to hospital. She's fine now," he told AFP by phone.

Around 190 people have been arrested since Sunday, according to Sapa news agency.