CAPE TOWN - US President Barack Obama visited a bleak former prison island off the coast of South Africa on Sunday to pay tribute to ailing anti-apartheid hero Nelson Mandela and set the stage for a speech urging Africans to strive for prosperity and democracy.
Obama is due to cite the legacy of Mandela, who was imprisoned on Robben Island for 18 of the 27 years he spent in jail before becoming the first black president of South Africa, in a speech at the University of Cape Town later in the day.
Current South African President Jacob Zuma was also held on the wind-swept island off Cape Town under the apartheid regime that ended in 1994 with Mandela's election victory.
Some protesters gathered outside the University of Cape Town ahead of Obama's speech, holding placards attacking US foreign policy reading "Obama mass killer" and "End drone wars now".
The 94-year-old Mandela's faltering health has been a sombre backdrop to Obama's eight-day Africa trip. South Africa's government says his condition is "critical but stable".