Protesters threw stones at motorists on the R114, between Malibongwe and Cedar roads, on Monday morning, Johannesburg metro police said.
"No-one was injured but it is not safe to drive there," said Superintendent Wayne Minnaar.
He said some 200 protesters became violent, and traffic had to be diverted.
The roads were first closed at 4:45am after protesters blockaded them with burning tyres.
...read more here: Protesters threw stones at motorists in Johannesburg

