Obama Lands in S'Africa Amid Mandela Vigils

 
US President Barack Obama has landed in South Africa, the second stop in his three-country tour of Africa.
Obama said earlier he did not expect to see former President Nelson Mandela, who is critically ill in hospital.
Leaving Senegal, he told reporters on board Air Force One: "I don't need a photo op."
Meanwhile, Mandela's ex-wife, Winnie Madikizela-Mandela said the former leader had made "a great improvement" in recent days, but was "still unwell".
But she said she felt it would not be right for the US president to visit Mandela while he was in a critical condition.
Correspondents say security is tight in the streets near Mediclinic Heart Hospital in the capital, Pretoria, where the 94-year old is being treated for a lung infection.
Ministers, politicians, Mandela's physician and family members were among those visiting the ex-leader on Friday, his 21st day in hospital.
Several hundred people earlier took to the streets of Pretoria in protest against Obama's foreign policy.
However, the BBC's James Copnall in the city says Obama does have wide support in South Africa.
Obama's plane landed at a military airbase near Pretoria on Friday evening. During his stay, he is scheduled to meet President Jacob Zuma and hold a major speech, correspondents say. He is also expected to visit Robben Island, where Mandela was imprisoned for 18 years.
However Obama said earlier he did not expect to see the ailing ex-leader during his South African trip.
"I don't need a photo op," he said aboard Air Force One after leaving Senegal. "The last thing I want to do is to be in any way obtrusive at a time when the family is concerned with Nelson Mandela's condition."
He went on to say: "I think the main message we'll want to deliver is not directly to him, but to his family - is simply profound gratitude for his leadership all these years, and that the thoughts and prayers of the American people are with him, his family and his country."
Officials and many South Africans have praised his decision to visit South Africa, our correspondent says.
Obama met Mandela in 2005 when he was still a US senator. Both men became the first black presidents of their nations and have received the Nobel Peace Prize.