Mpumalanga police have arrested 38 people in Kwaggafontein after they torched offices, vandalised computers and looted foreign-owned shops.
The unrest started on Monday and continued into the early hours of Tuesday morning.
Residents are protesting over a lack of services in the area.
The demonstrations have also spread to nearby areas, including Baberton.
The police’s Leonard Hlathi says: “The Kwaggafontein protest continued up until the early hours of the morning. Our police were busy making sure that the area is declared safe; the road which was barricaded, the Moloto Road, has been opened.
“Our police will remain in that area up until everything returns to normalcy.”