Malawi says it will repatriate its nationals from South Africa, following an upsurge in xenophobic violence.
At least five foreigners, including a 14-year-old boy, have been killed in attacks in South Africa's coastal city of Durban since last week.
Some foreign-owned shops in the main city Johannesburg have shut amid fears that the violence could spread.
Zimbabwe has also condemned the attacks, blamed on locals who accuse foreigners of taking their jobs.
Tens of thousands of foreigners, mostly from other African states and Asia, have moved to South Africa since white-minority rule ended in 1994.
At least 62 people died in xenophobic attacks that swept South Africa in 2008.
Malawi is the only country which has so far decided to repatriate its citizens.
Information Minister Kondwani Nankhumwa said the first group would return at the weekend.
About 420 Malawians are reportedly living in refugee camps in Durban after fleeing the violence, he said.
The BBC's Raphael Tenthani reports from Blantyre that he received a call from a Malawian in Durban who said saw he some Malawians being killed - including a close friend who was burned alive.
Mr Nankhumwa called on the African Union (AU) and the Southern African Development Community (Sadc) to intervene to help protect foreigners.
"This is unfortunate coming at a time we are working on regional integration," he said at a press conference.
"We urge the government of South Africa to protect foreigners," he added.
At the scene: Milton Nkosi, BBC News
Standing in the middle of a football field that has been turned into a refugee camp overnight in Durban's Chatsworth township, one cannot help but feel ashamed of being South African.
There are white and green tents dotted around housing destitute African migrant families who fled the violence meted out to them by their South African hosts.
Two weeks ago locals began attacking and looting properties owned by fellow Africans, calling them "kwerekwere", a derogatory word for African migrants.
I did not even have to ask Memory Mahlatini, a Zimbabwean who works as a nanny, what happened to her because her story was written all over her face.
Her eyes alone made me look down in shame as she explained how a group of South Africans came to her rented home last Monday evening just as they were preparing to sleep and demanded that they go back to where they came from.
In total, the violence has left about 5,000 foreigners homeless in Durban, the main city in South Africa's KwaZulu-Natal province, local media reports.
On Wednesday, the violence spread to the province's second city, Pietermaritzburg, where foreign-owned shops were looted.
Verulam, a town about 30km (18 miles) north of Durban, has been hit by similar violence.
The government has ordered police to step up patrols to prevent the violence from escalating.
The governing African National Congress (ANC) said in a statement that South Africans should "hang our heads in shame in the face of these misguided and misplaced assaults".
Zulu King Goodwill Zwelithini has been accused of fuelling xenophobia after he was widely quoted as saying at a meeting last month that foreigners should "please go back to their countries".
He denied being xenophobic and claimed he had been mistranslated.
South Africa's official unemployment rate stands at 24%, but some analysts believe that it is much higher.