Johannesburg - Police in Kagiso, west of Johannesburg, arrested 21 people in an anti-crime sweep of the area on Friday, a spokesperson said.
Constable Lucky Matome said 10 of the people in custody were arrested for serious crimes, such as possession of an unlicensed firearm and ammunition, and possession of a hijacked vehicle.
They also arrested people for being in possession of illicit cigarettes and dagga.
Eleven migrants, without the proper documents, were also taken into custody.
Major General Anna Mateisi, cluster commander of Krugersdorp, which Kagiso falls under, said teamwork was the largest contributing factor to the success of the multi-agency operation.
Friday's operation follows a similar one further west, in Randfontein on Thursday, with a special focus on second hand dealers, scrap yards, spaza shops and unlicensed hawkers.
In that operation, spokesperson Captain Appel Ernst said they arrested people for dealing in illicit cigarettes, contravention of the Liquor Act, dealing in dagga, possession of drugs and dealing in counterfeit DVDs.
Forty-four people were arrested in that operation, including undocumented migrants.
The sweeps form part of the controversial Operation Fiela, set up after a spate of xenophobic attacks across the country in April.
After that, the presidency decided that after speaking to residents in the affected communities, a common complaint was that there was a lot of crime in their communities and they wanted something done with it.
However, Lawyers for Human Rights had to apply to court to enforce the rights of the migrants arrested in raids in central Johannesburg, and also challenged the broadness of the operation.
They believed it should have been conducted in a more targeted way.
Minister in the Presidency Jeff Radebe has described Operation Fiela as an "operation to rid our country of illegal weapons, drug dens, prostitution rings and other illegal activities".
It has been held across the country, with arrests being reported every day.