South African troops have been deployed to areas around Johannesburg where more than 10 days of anti-foreigner violence has left at least 42 people dead.

Officials say the troops began joint patrols with police Thursday in at least three Johannesburg townships.

President Thabo Mbeki approved the deployment of troops on Wednesday to help end mob attacks on foreigners.

Police say Gauteng province - the center of the violence - was mostly calm overnight Wednesday. But new incidents have been reported elsewhere, including the eastern port city of Durban, where dozens of foreigners sought protection at a local police station.

Thursday, the deputy president of South Africa's ruling African National Congress party called the anti-foreigner violence one of the ugliest incidents in the nation's post-apartheid era.

In comments to an international media conference in Johannesburg, Kgalema Motlantha also criticized law enforcement's delayed response to the violence.

South African relief agencies are appealing for donations to help supply aid to the estimated 16,000 people displaced by the attacks. Red Cross officials say they need at least $500,000 for attack victims.

Many of those targeted are immigrants from Zimbabwe and Mozambique. Attackers are accusing the immigrants of taking jobs and increasing South Africa's already-high crime rate.

Officials in Mozambique say hundreds of Mozambicans have voluntarily returned home to escape the mob attacks.

Some information for this report was provided by AFP, AP and Reuters.