Protesters blocked roads with burning tyres and rocks in a show of opposition to President Jacob Zuma hours before the South African parliament was due to vote on a no-confidence motion which could force him to step down.
The ANC has 249 seats in the 400-seat parliament and the opposition controls 151 seats, so it would take 50 ANC lawmakers backing the opposition to vote Zuma and his cabinet out.
If the motion is successful, Zuma would be removed as state president but would remain as ANC leader until December, when he is due to step down and a new leader elected in his place.
Zuma’s has survived eight no-confidence votes during his eight years tenure as South Africa’s president and he is due to run until 2019, when national elections will be held.
Should he be forced to quit as South Africa’s president, the speaker takes over and the National Assembly is expected to elect a new national leader within 30 days.