S Africa prays as Mandela's health remains critical

South Africa's freedom crusader and former President Nelson Mandela remains in critical condition at a Pretoria hospital, according to latest bulletins, even as the nation is united in an anxious vigil.

The Nobel laureate has been hospitalized since 8 June for a recurring lung infection. Previously, authorities had described Mandela's condition as serious but stable; but over the weekend, his health took a turn for the worse.

"Former president Mandela remains in a critical condition in hospital," President Jacob Zuma told the nation today. "The doctors are doing everything possible to ensure his well-being and comfort."

He declined to comment further.

Zuma's office also dismissed suggestions that US President Barack Obama could cancel his visit to South Africa this week in view of the fading health of Mandela, adored at home and respected globally.

Obama is due to arrive in South Africa on Friday with his wife and two daughters for his first substantive visit to Africa since he took office.

Mandela, 94, has become increasingly frail over the years and has not appeared in public since South Africa hosted the World Cup in 2010.

A senior official said South Africans should not hold out "false hopes".

South Africa's first black president was taken to hospital in Pretoria earlier this month for the third time this year. On Sunday, the presidency announced that Mandela had become critical, after Zuma visited him in hospital.

Outside the hospital, a security wall was awash with get-well cards, balloons, flowers, cards and paintings, the South African Press Association reported.

For Mandela's family, these are very personal times -- times to be cherished as the end nears.

"All we do every day is take one day at a time and pray to the good Lord," said his daughter Makaziwe Mandela. All I pray for as a daughter is that the transition is smooth. ... he is at peace with himself. He has given so much to the world."