Sporadic violence has broken out in Johannesburg as more than 50,000 people marched in South African cities to protest against President Jacob Zuma on Friday, demanding he quit after a cabinet reshuffle triggered the latest crisis of his presidency.
Mr Zuma's sacking of Finance Minister Pravin Gordhan in the reshuffle last Thursday has outraged allies and opponents alike, undermined his authority and caused rifts in the ruling African National Congress (ANC), which has governed South Africa since the end of white-minority rule in 1994.
Fitch on Friday followed S&P Global Ratings and downgraded South Africa to "junk", citing Gordhan's dismissal as one reason. S&P had issued its downgrade on South Africa in an unscheduled review on Monday.
In Johannesburg, police "fired rubber bullets at protesters who were attacking other protesters with stones. Four protesters sustained minor injuries," Johannesburg Metro Police Department spokesman Wayne Minaar said. Some ANC backers were trying to breach a cordon separating them from members of the opposition Democratic Alliance.
Elsewhere in the city, the marches were peaceful.