A protest in Atlantis, around 40km north of Cape Town, has left most roads in the area closed, Western Cape traffic chief Kenny Africa said on Thursday morning.
"The situation is very tense and there is a high presence of police and traffic in the area," he said.
It is not immediately clear what the reasons for the protest are.
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Africa said the following routes and areas are affected: Old Mamre/Darling Road, Starling Road and Section C, Klein Dassenberg, N7 Rondeberg, John Dreyer Road and industrial area, Witsand.
Cape Town traffic services spokesperson Maxine Jordaan said Old Mamre/Darling Road was closed between Philadelphia and Starling Road, and Klein Dassenberg closed at the N7.
Motorists have been asked to make use of alternative routes.