South Africa fire: What are Johannesburg's hijacked buildings?

Focus on Africa - A podcast by BBC World Service

Many buildings in the centre of the South African city of Johannesburg, where a horrific fire has killed more than 70 people, are deemed unfit to live in. Yet these old blocks, abandoned by their owners or the city authorities, are full of families often paying rent to criminal gangs who run them. The buildings, which lack running water, toilets or a legal electricity connection, are then said to have been "hijacked". We find out what this means. A private plane found with more than $5m in cash, fake gold, guns and ammunition on board, is at the centre of a deepening investigation in the Zambian capital, Lusaka. The African Climate Summit will take place in the Kenyan capital, Nairobi next week, featuring speakers from Kenya’s government, the African Union and the United Nations. Will the event be just hot air or will it provide a solid plan of action?