A demonstration against undocumented migrants in South Africa descended into violence Thursday with one foreign national arrested and a community leader saying five Congolese were hurt.

The protest was in the port city of Durban which has been at the epicentre of weeks of action against irregular migration in which at least four foreign nationals have been killed and tens of thousands have fled the country.

Police said about 100 marchers from an anti-illegal migrant group went on what they called “a clean-up campaign” against an encampment of several hundred foreign nationals outside a government office.

Foreigners, many of them from the Democratic Republic of Congo (DRC), moved to the site 13 weeks ago to seek protection against mobs of South Africans campaigning against undocumented migrants.

“During the commotion, stones were thrown around, and one which was thrown by a foreign national landed on a police officer,” police said.

The person was arrested, a statement said, without giving details.

A leader of the group of foreigners told AFP that five Congolese nationals including two children were hurt in the clash.

“The march today was very violent,” said Bishop Raphael, who is from the DRC.

“They found us here and immediately attacked our people. We are not committing any crime by being here. This is uncalled for,” he said.

Many of the people in the group claim to be refugees from the DRC.