Jacob Zuma leads ANC in honouring Nelson Mandela Mr Zuma opened the African National Congress' five-yearly leadership conference with an old struggle song that commemorates Mr Mandela's fight against apartheid, bringing some 4,500 delegates to their feet. The 94-year-old was admitted to hospital earlier this month in Pretoria for what was initially described as routine tests. The South African presidency later disclosed he was being treated for a lung infection, and on Saturday said he had successfully undergone an endoscopic procedure to remove gallstones. Mr Zuma is being challenged for party presidency by his deputy, Kgalema Motlanthe, at the elective conference under way in the city of Bloemfontein, also known by its African name Mangaung. Mr Motlanthe, who previously served as the country's caretaker president, appeared to be losing the battle for support on the convention floor, with most of the delegates loudly supporting the incumbent. In a speech that began three-and-a-half hours late, Mr Zuma sought to quell divisions in the party and stop "bad tendencies," such as political violence and vote-buying, that have crept into the ANC, which this year marks its 100th anniversary. "We've experienced the shocking occurrences when armed comrades disrupt ANC meetings," he said. What could possibly be so important that people would risk lives through the use of violence to get their own way? One of South Africa's wealthiest businessman, Cyril Ramaphosa, a former miners' union leader, gave a boost to Mr Zuma on Sunday by agreeing to run for the ANC deputy presidency. Meanwhile Trevor Manuel, the internationally respected former South African finance minister who is currently in charge of national planning, declined his nomination to the ANC's executive committee and criticised the fierce competition for leadership he said was destroying party values. Mr Zuma in his speech also sought to dispel investor concerns that South Africa is "falling apart" because of downgrades by ratings agencies amid sluggish economic growth.