More than 20,000 Mozambicans have fled South Africa
South Africa has given fresh figures on the numbers of people killed and displaced by the wave of attacks on foreigners over the past two weeks.
Safety and Security Minister Charles Nqakula told the BBC 56 people had been killed and more than 650 injured. Previously, 50 deaths were reported.
More than 30,000 had been displaced or forced from their homes, he said.
Other organisations said this was a gross under-estimation and that at least 80,000 had been displaced.
According to South Africa's Centre for the Study of Violence and Reconciliation (CSVR), as many as 100,000 Africans may have been driven from their houses.
The organisation says it has done a careful count in the Johannesburg area and other organisations have conducted similar tallies in Cape Town and Durban.
Adele Kirsten, the centre's executive director, said the government had been "incredibly slow to respond".
"They have certainly failed to grasp the seriousness of the situation," she told the BBC's World Today programme.
Mr Nqakula said that more than 1,300 arrests had been made and special courts had been set up to deal with the situation.
Aid agencies say large numbers of Zimbabweans have been leaving for Zambia, with others heading for Mozambique and Botswana.
On Sunday, South African President Thabo Mbeki denounced the anti-immigrant violence as a disgrace that had blemished the name of South Africa.
Mr Mbeki chaired a meeting of a government task force on Monday to discuss the crisis.
Speaking afterwards, Mr Nqakula said the situation was "now under control".
He added that no accurate picture was yet available on the precise ethnic make-up of those who had fled.
Many people have left the country altogether, turning their backs on South Africa - a country they once thought of as home, BBC Africa editor Martin Plaut reports.
Aid agencies have spoken of large numbers of Zimbabweans leaving for Zambia, with others heading for Mozambique and Botswana.
Mozambique's government says about 20,000 of its own citizens have fled South Africa.
It has set up transit camps near the capital, Maputo, to accommodate the fleeing migrants.
In Cape Town, South Africa, the authorities and charities have begun efforts to feed and shelter the displaced.
South African police raiding the home of a suspect
At least 10,000 immigrants fled to makeshift camps outside the south-western city alone.
South African President Thabo Mbeki made his comments on Sunday in a national radio and television address.
He said the attacks were the worst acts of inhumanity South Africa had seen since the end of apartheid.
The president has been criticised for his handling of the crisis, including a response which some have seen as slow.
The BBC's Will Ross in Johannesburg says some in South Africa wonder why it took him two weeks to make this address to the nation.
Our correspondent says there is a great deal of xenophobia in South Africa and foreigners are often accused of taking away people's jobs and fuelling crime.
But despite this perception, he adds, most South Africans have been utterly appalled by the violence.
The troubles flared with a wave of attacks on foreigners in the township of Alexandra, within sight of some of Johannesburg's most expensive suburbs.
They have since spread to seven of South Africa's nine provinces.