Cape Town - Authorities in Johannesburg arrested 102 people on Friday night in a crackdown on several so-called "hijacked properties" on Davies Street in Doornfontein.These are buildings that have been abandoned by their rightful owners and taken over by slumlords."Hijacked buildings are a major challenge in our inner city, with our people living in deplorable conditions and being abused by slumlords," said Johannesburg Mayor Herman Mashaba in a statement on Saturday morning.Of the 102 arrests, 98 were of undocumented migrants, two for the possession of illegal drugs, one for a fraudulent health certificate, and one for allegedly being behind the "hijacking" of a building and acting as a slumlord.The operation was jointly carried out by the police, the Department of Home Affairs, the Johannesburg Metropolitan Police Department, and others.Mashaba said immigration officers would process the undocumented migrants who were detained, but did not give further information.He said the hijacked buildings in and around Johannesburg's central business district, many of which are rundown and overcrowded, should be turned into quality low-cost housing for residents and affordable rental spaces for small businesses."If we are going to turn around the decay of our inner city, it is vital that the rule of law is respected. I see the revitalisation of the inner city as key to ensuring economic growth and job creation in Joburg," he said. The raid occurred on the same day that Deputy Police Minister Bongani Mkongi, speaking in Hillbrow next to Doornfontein, accused foreign nationals of taking over parts of the inner city from South Africans.