Port Elizabeth - A municipal building in Kirkwood was set alight during service delivery protests on Tuesday, Eastern Cape police said.
Warrant Officer Basil Seekoei urged motorists to use alternative roads and members of the public to avoid the town's central business district.
Burnt tyres and wood were strewn along the town's main roads.
The protests began in the early hours of Tuesday morning, he said.
Rubber bullets were used to disperse the crowd.