As hawkers from all over Africa scattered for cover, trying to protect their stock, a trader from Senegal was beaten until he bled, and had bricks thrown at him. The attack on Monday was the second by South African street sellers on foreign hawkers in less than a week.
The previous Wednesday six were arrested after shop windows were smashed, stalls overturned and foreign vendors attacked when hundreds of hawkers went on the rampage after a meeting in Johannesburg to protest at the influx of "alien" sellers onto the streets. By the afternoon usually bustling streets were eerily silent.
Xenophobes all over the world seem to share the same dictionary. Mannekie Solomon, chairman of the Inner Johannesburg Hawkers Committee, told the Sowetan newspaper that foreign traders were "leeches", who dirtied the streets and stole South African jobs. He and his members had not fought in the liberation struggle to let this happen.
In a country where official unemployment is more than 35 per cent and jobs in the formal sector scarce, scapegoats are being sought.
Johannesburg Council estimates 14,000 traders from around the world are now making R100m (pounds 13.5m), tax free, from selling everything from roasted mealies (corn cobs) to leather handbags.
The two attacks are the first dramatic signs of the savage competition for work. More worrying, they highlight the growing xenophobia of black South Africans towards migrants from other parts of the continent, whom they blame for everything from rising crime to unemployment.
This week the South African Human Rights Commission said the attacks were a fundamental abuse of the human rights of immigrants, who were protected under South Africa's celebrated new constitution. A spokesman said the attacks dented the international image of South Africa, particularly in Africa. One outraged black journalist, who witnessed the first attack, was clearly ashamed. "Are we not all Africans?" he said.
South Africa has experienced a flood of illegal African immigrants fleeing economic and social instability. Last year 180,713 were repatriated.
The majority came from Mozambique and Zimbabwe, although some have trekked from as far as Ethiopia. Those who are expelled are believed to be just the tip of the iceberg. Estimates of how many illegal immigrants are in the country range from 500,000 to 6 million.
Some take desperate risks. The first attack in Johannesburg city centre came as Kruger National Park revealed a pride of lions had been put down after eating a Mozambican man trying to cross illegally into South Africa. The lions were believed to be responsible for killing three other Mozambicans.
In the past nine months 11 people have been eaten by wild animals while trying to enter South Africa illegally, including a woman and her two- year-old son. There are also reports of Zimbabweans trying to swim the Limpopo River being eaten by crocodiles.
The influx of illegal immigrants - and the widespread xenophobia - is causing much soul searching. It costs South Africa at least R200m a year to remove illegals, who invariably turn up again weeks later.
As the army and police struggle to patrol the huge border more radical solutions are being suggested. Some academics claim it would be better to accept the border cannot be maintained, and allow immigrants to come in without penalty. They argue that the numbers involved are exaggerated and that the same people are being repatriated again and again.
Christian Rogerson and Talibre Toure, researchers at the University of the Witwatersrand in Johannesburg, challenge the notion that immigrants are a drain on the system. They claim immigrants actually create employment through their small businesses. Other recent research concluded migration was good for the economy because it brought in people with initiative.
Religious leaders, meanwhile, are appealing to a sense of fair play and attention to recent history. "While unemployment is a crisis for South Africa, that is no reason for the callous ill treatment of economic refugees who come to South Africa," said Bishop Mvume Dandale of the Southern Africa Methodist Church.
Reverend Paul Verryn, the Methodist bishop whose parish covers Johannesburg city centre, said attackers should remember that many African states had aided the struggle by protecting, housing and employing some of the country's current key leaders. The implication was clear: this was hardly the way to repay past favours.