A 31-year-old man was arrested on Wednesday, in connection with the rape of a seven-year-old girl at the GPO informal settlement.
Police are monitoring the situation in Capricorn near Muizenberg in the Cape Peninsula after violence flared up again on Monday.
The City of Cape Town says it is impossible to manage a city or government while infrastructure is being destroyed.
Cape Town firefighters have had to abandon efforts to fight a blaze which razed a community clinic in the Joe Slovo settlement after they were pelted with stones.
A community hall has been torched and vehicles stoned as authorities moved to rein in a protest in Cape Town.