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Soweto (South Africa) (AFP) - 1127 GMT: Obama is walking towards the podium to address the crowd, TV pictures show. 1120 GMT: Adriaan Basson, South African author of the book "Zuma Exposed", tweets: "This is hugely embarrassing. President Zuma booed again after being introduced by Cyril Ramaphosa. 1113 GMT: Ramaphosa again appeals for calm from the crowd as Zuma's ex-wife, African Union Commission chairperson Nkosazana Dlamini-Zuma, speaks.
JOHANNESBURG (AP) — World leaders, family, friends and thousands of mourners who queued for hours to secure a seat in Johannesburg's FNB stadium paid tribute to South Africa's anti-apartheid icon Nelson Mandela.