Berlin  - The German Foreign Ministry issued a warning to travellers to South Africa Tuesday to avoid central Johannesburg and the outlying black townships, following an outbreak of violence against immigrants.

Over the past few days there had been serious outbreaks of violence directed against black immigrants and ethnic minorities in townships on the outskirts of cities like Johannesburg and Pretoria and also in central Johannesburg, the ministry said.

It advised against all trips to these areas, whether organized by tour groups or undertaken alone.

Around 30 people have died in the violence, which has been largely directed at Zimbabweans fleeing the chaos in their own country, which borders South Africa to the north.

Citizens of Mozambique, South Africa's north-eastern neighbour, have also been caught up in the conflict, which has led thousands to flee their homes to seek shelter. (dpa)