Barack Obama's visit to South Africa – in pictures

Barack Obama in the Robben Island cell where Nelson Mandela spent 18 years of his 27-year prison term Photograph: Carolyn Kaster/AP

Obama and his wife, Michelle, tour Robben Island Photograph: Saul Loeb/AFP/Getty Images

Obama writes in a guest book Photograph: Jason Reed/Reuters

The note left by the Obamas in the guest book Photograph: Saul Loeb/AFP/Getty Images

President Back Obama walks by bar covered windows Photograph: Carolyn Kaster/AP

Obama looks at a computer with youths as he tours the Desmond Tutu HIV Foundation youth centre and takes part in a health event in Cape Town Photograph: Jason Reed/Reuters

Obama embraces Desmond Tutu Photograph: Saul Loeb/AFP/Getty Images

A man wearing a Obama T-shirt outside the Medi-Clinic heart hospital where Mandela is being treated in Pretoria Photograph: Kevin Coombs/REUTERS

Marine One, with the Obamas on board, flies over Pretoria Photograph: Saul Loeb/AFP/Getty Images

Protesters outside Johannesburg University in Soweto before Obama's meeting with students Photograph: Jeff J Mitchell/Getty Images

Helicopters including Marine One in front of the Union Buildings in Pretoria Photograph: Dan Kitwood/Getty Images

Protesters scuffle with police outside Johannesburg University in Soweto Photograph: Jeff J Mitchell/Getty Images

A South African government-issued photo of President Jacob Zuma and his wife, Tobeka Zuma, with the US first couple in Pretoria Photograph: Elmond Jiyane/EPA

Protesters outside Johannesburg University in Soweto Photograph: Christopher Furlong/Getty Images

Obama and Zuma give a press conference at the Union Building in Pretoria Photograph: Saul Loeb/AFP/Getty Images

Police use stun grenades in an attempt to disperse protesters outside the University of Johannesburg Photograph: Dylan Martinez/Reuters

Obama answers questions at the University of Johannesburg in Soweto Photograph: Chip Somodevilla/Getty Images

A young man shows his excitement as Obama calls on him for a question Photograph: Chip Somodevilla/Getty Images

Sasha Obama and her cousin Leslie Robinson listen to Michelle Obama speak at a youth event Photograph: Carolyn Kaster/AP

Michelle Obama waves to participants after a discussion event with young people at the Sci-Bono Discovery Centre in Johannesburg Photograph: Thomas Mukoya/Reuters

Michelle Obama hugs Tebogo Tenyan, 16, during a youth event Photograph: Carolyn Kaster/AP

Obama answers questions from the audience and from people in Nigeria, Uganda and Kenya via video link at the University of Johannesburg Photograph: Chip Somodevilla/Getty Images

The Obamas at an official dinner hosted by Zuma in Pretoria Photograph: Evan Vucci/AP