JOHANNESBURG, South Africa (CNN) -- South Africans protesting the violence against foreigners marched in the streets of Johannesburg on Saturday, carrying signs saying, "Stop the Senseless Killing," "Mr. Mbeke, Where are You?" and "Shame on Us."

Residents take to the streets of Johannesburg on Saturday to protest violence against foreigners.
Critics of President Thabo Mbeki say he hasn't shown enough leadership as evidenced by his waiting until Wednesday to call out the South African National Defense Force to help police.
The soldiers were deployed to Johannesburg for the first time since apartheid ended in 1994. They and police have been using rubber bullets to disperse rampaging mobs and ward off extensive looting.
Police reassessing the xenophobic attacks in South Africa said Saturday that at least 50 immigrants have been killed amid accusations that foreigners have been usurping jobs and housing from residents.
All the deaths have been in the small province of Gauteng, where the attacks began May 11 in Johannesburg's Alexandra Township.
It has since spread to six more provinces: Western Cape, Free State, North West, Limpopo, Kwazulu-Natal and Mpumalanga.
On Friday night, a soldier helping police keep the peace shot to death a man who allegedly was attacking a woman, the army said Saturday. However, it was unclear whether his actions were related to the recent spate of attacks against immigrants.
Incidents of foreigners' homes being torched were reported Friday night in the Johannesburg area and Kwazulu-Natal.
Watch analysis of reasons behind xenophobic attacks »
Thousands of immigrants, many of whom fled to South Africa from troubled Zimbabwe, have been streaming back to their home countries, many on buses provided by Zimbabwe, Mozambique and Malawi.
The estimated number of immigrants displaced by the violence ranges from 17,000 from the South African Police Service to 28,000 from the Ministry of Safety and Security. Desperate stories of those fleeing violence
More than 400 arrests have been made for crimes ranging from murder to causing a public disturbance, said Ministry spokesman Hangwani Malaudzi.

Zimbabwean opposition leader Morgan Tsvangirai, who returned to his country Saturday from Johannesburg, blamed Zimbabwe President Robert Mugabe for the repressive regime and devastated economy that prompted so many citizens to go to South Africa seeking a better life.
Mbeke said Saturday the anti-immigrant violence was a disgrace.
CNN's Nkepile Mabuse contributed to this report.
All About South Africa • Zimbabwe • Africa
| Most Viewed | Most Emailed |