A wave of xenophobic attacks spread through South African townships on Monday and mobs beat foreigners and set some ablaze in scenes reminiscent of apartheid era violence.

Two people were killed and more than two dozen shacks were torched in the Tembisa township near Johannesburg, the South African Broadcasting Corp. said. Police, struggling to restore order, said at least 13 people were killed over the weekend.

Immigrants from African neighbours are accused by many in the townships, among South Africa's poorest areas, of taking jobs and fuelling the high rate of violent crime. Local media report about 20 dead since trouble broke out a week ago.

The unrest is an embarrassment for a country that has vaunted its tolerance since the end of apartheid and an indicator of growing disaffection among South Africa's poor.

President Thabo Mbeki and ruling ANC party leader Jacob Zuma have called for an end to the violence, which threatens a new strain on an economy struggling with rising inflation, power outages and a skills shortage.

Hundreds of immigrants have taken refuge in police stations, churches and government offices.

'At the moment some of the people have been taken to the city hall as a place of safety, but some of them are still running around and do not know where to go,' police spokesman Veli Nhlapo told SABC.

Police fired rubber bullets at gangs of youths, who patrolled unruly streets, armed with sticks, rocks and knives. Scores have been arrested in connection with the violence.

South African newspapers carried photos of a man who was set alight by a mob on the weekend. Callers to radio stations urged authorities to impose curfews and bring in the army to restore order in some of the most violent areas.

Among the immigrants are an estimated 3 million Zimbabweans who fled economic collapse at home. The immigrants say they more often the victims of crime than perpetrators.

The Zimbabweans, like others on the continent, have been lured by work in South Africa's mines, farms and homes, and by one of the world's most liberal immigration and refugee policies. Aid group Medecins Sans Frontieres said the situation in the townships now amounted to a humanitarian crisis.- Reuters