More than 40 foreigners have been killed in gang attacks in South Africa in the last week. Several thousand terrified immigrants are now reported to have fled the country, says Christian development agency World Vision.
Most of the violence has taken place in townships in the poorest parts of Johannesburg.
Shops owned by foreigners have been burnt to the ground and in perhaps the most vicious attack, a man was burnt alive.
The violence began a week ago in the sprawling township of Alexandra, where people from South Africa's neighbouring countries were set upon by angry mobs blaming foreigners for crime and unemployment.
Most of the immigrants are from Zimbabwe, Mozambique and Malawi.
Many Zimbabweans have previously fled dire economic circumstances in their home country. It is thought that between three and five million Zimbabweans are now living in South Africa.
World Vision believes that the underlying causes of the sudden eruption of violence include high unemployment, high food prices, unequal distribution of housing in the townships, high numbers of immigrants and upcoming elections.
The organisation is meeting with the UN refugee agency, the South African Council of Churches and government officials to discuss how best to proceed.
World Vision says it will also work with churches and faith-based organisations to explore the provision of aid to people who have been displaced.