Those responsible for "acts of violence and violations of human rights" during the looting of foreign-owned shops in Soweto last week must be brought to account, the UN Refugee Agency (UNHCR), said on Tuesday.
"We urge all possible efforts to avert future attacks, including incitement or attempts to block peaceful solutions. If unchecked, such xenophobic attacks could lead to further damage and destruction," spokesperson Charlie Yaxley said.
Last Wednesday, violence broke out during protests in White City, sparked by allegations that shop owners sold expired food to the public.
Rubber bullets and tear gas were fired to disperse crowds gathered at different shops in the area.
The rioting and looting resulted in the deaths of four people, police have confirmed.
The UNHCR said in a statement that it was supporting government efforts to assist people who have been displaced or who have been affected by displacement.
Its staff have visited refugees and asylum-seekers affected by the unrest in Soweto to assess their situation and needs, Yaxley said.
"Many foreign shop owners have been affected by the violence and their small shops – often their only means of livelihood – have been looted and destroyed."
According to UNHCR's data, just over 280 000 refugees and asylum-seekers are currently living in South Africa.