South African police have rounded up 100 undocumented foreign nationals in a township north of Johannesburg following days of protests about the murder of a police officer.

Captain Oupa Matjie was murdered in Diepsloot during a confrontation with a suspected robber. Residents accused a Zimbabwean man of killing him - his photograph was widely circulated on social media.

Disgruntled residents took to the streets and targeted informal businesses owned by foreign nationals, who are often blamed for every social ill in poor communities.

Many South Africans who live in the area have condemned the targeting of foreigners, others have warned African migrants to behave or leave the country.

It is unclear what will happen to the migrants who have been arrested.

On a number of previous occasions, when police have detained groups of foreigners, they have been released quietly back into the community.

But the situation remains tense in Diepsloot after officers raided homes on Tuesday morning in search of undocumented foreigners. (Text, excluding headline, courtesy of BBC)