Johannesburg - A protest by residents in Riverlea, south-west of Johannesburg, is underway on Nasrec Road near the N17, metro police said on Monday.
"There are protesters throwing stones at passing cars and burning tyres," Chief Superintendent Wayne Minnaar said.
Motorists were urged to use alternative routes.
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The protests began around 06:00, Minnaar said.
The reason for the protest was not immediately clear.