South African troops helped embattled police on Thursday in trying to quell a wave of violence against immigrants that has claimed 42 lives and displaced 16,000.

For the first time since unrest broke out more than 10 days ago, soldiers deployed on Johannesburg's streets to help stem a tide of violence that has seen mobs of armed youths attack foreigners in poor areas around the city.

About 200 soldiers assisted police with morning arrest and search operations in central Johannesburg and were on standby for the evening amid uncertainty about whether the situation had been brought under control, the army said.

"It is calm now but this is very sporadic so it can change in another hour or so," a spokesman for the defence forces, General Kwena Mangope, told AFP.

"We are on stand-by for this evening. It will be determined by the police as and when they need us."

President Thabo Mbeki bowed to pressure to call in the army on Wednesday after a request for support from the police force.

It appeared that the mass outbreak of arson attacks, looting and assualts witnessed around Johannesburg earlier this week had been brought under control Thursday, but pockets of unrest were reported in other areas of the country.

Anti-foreigner incidents were reported for the first time in North West province and the central area of Free State on Thursday.

A spokesman for North West police, Brian Dlamini, said 49 people had been arrested on Wednesday night for looting and burning shops belonging to foreigners.

In Free State, police said 22 people had been arrested after a group of people were seen throwing stones at the shops of Pakistanis.

"We are investigating charges of public violence currently but also looking into the possibility of xenophobia," police spokesman Motantsi Makhele told domestic news agency SAPA.

Zimbabweans, Mozambicans and Nigerians have been targeted in the violence, which spread outside of the Johannesburg region for the first time on Tuesday to neighbouring provinces.

The death toll from more than 10 days of violence nearly doubled on Wednesday to reach 42, and an estimated 16,000 people have been displaced, with many taking shelter at police stations, community centres and temporary camp sites.

Foreigners in South Africa, many of whom have fled economic meltdown in neighbouring Zimbabwe, are being blamed for sky-high crime rates and depriving locals of jobs.

The unofficial unemployment rate in South Africa is believed to be about 40 percent.

The violence, which has done untold damage to South African's reputation as the Rainbow Nation, is also taking its toll on the country's economy.

Unions and several mining companies reported Thursday that gold mines around Johannesburg, the country's economic heartland, had been hit by the unrest, with employees failing to show up for work.

National Union of Mineworkers spokesman Frans Baleni told AFP that one mine on the eastern outskirts of Johannesburg, which has a workforce consisting up to 90 percent of Mozambicans, "has not been operating since Monday."

An estimated 3,000 Mozambicans have fled South Africa to return home and Mozambican President Armando Guebuza said Thursday that the government was ready to assist its expats in returning.

The country's tourism minister has also warned of the impact on visitor numbers and a farming group raised alarm Thursday about the impact of xenophobia in the agricultural sector.

Turning to the reasons for the violence, the vice president of the ruling African National Congress party, Kgalema Motlanthe, laid the blame on the poor living conditions in slum areas.

"Limited public amenities and resources are at the core at this," he told a media forum in Johannesburg on Thursday.

Meanwhile, Zimbabwe opposition leader Morgan Tsvangirai linked the violence to the economic and political crisis in his homeland which has sent millions of Zimbabweans over the border into South Africa.

"The causes for this crisis are none other than our political crisis back home," said the former trade union leader as he visited Alexandra, a slum area in northern Johannesburg where the violence began last week.

PHOTO CAPTION:

An injured man receives medical attention on the outskirts of Johannesburg

AFP