South African president Jacob Zuma has cancelled a foreign trip in order to deal with the wave of attacks on immigrants that have killed at least six people.
In the latest violence, mobs attacked shops owned by foreign nationals in a poor area of Johannesburg.
Mr Zuma had been scheduled to leave for Indonesia last night to attend a meeting of African and Asian leaders but will instead stay to campaign for a peaceful resolution to the unrest that has swept several areas of South Africa in the past week.
The president plans to visit immigrants staying in a camp in the Chatsworth area of the coastal city of Durban, where some of the worst violence has taken place.
“These attacks go against everything we believe in. The majority of South Africans love peace and good relations with their brothers and sisters in the continent,” he said.
There was a heavy police presence in the Alexandra township of Johannesburg after rioters looted some shops, burned tyres and built street barricades on Saturday night and into yesterday morning, according to South African news reports.
Police were said to have fired rubber bullets in an attempt to stop the unrest.
Several shops and cars owned by immigrants have been torched in central Johannesburg in recent days.
Attacks on immigrants, many of them from other African countries, in and around Durban have subsided after the deaths of six people there, police said. Some 112 people were arrested in KwaZulu-Natal province, which includes Durban, during the riots there, according to the authorities.
Some South Africans have accused immigrants of taking jobs and opportunities away from them in a country with high unemployment.
The government has said it is addressing complaints about undocumented migrants, while noting that many foreign nationals are living legally in South Africa and contributing to economic development.
About 60 people died in similar unrest in South Africa in 2008.
In January this year, four people died during a week of looting of foreign-owned shops and other violence in Soweto and other areas of Johannesburg.
The violence this month has prompted some African countries to make arrangements for the return of their citizens from South Africa. Many immigrants are from neighbouring Zimbabwe. Its president, Robert Mugabe, said he was glad the South African government had denounced the violence.
Mr Mugabe is currently chairman of the African Union as well as a regional group, the Southern African Development Community.
“If there is any issue arising from the influx of Africans into any country, surely that can be discussed and measures can be taken, and taken amicably, to deal and address the situation,” Mr Mugabe said in remarks on the 35th anniversary of Zimbabwe’s independence.
South Africa’s home affairs minister Malusi Gigaba said more than 300 people had been arrested in connection with violence against immigrants from other parts of Africa.
He warned that those responsible for the violence would be subject to “the full might of the law”.