- South African President Jacob Zuma has sought to reassure an uneasy nation that Nelson Mandela, although in a "very serious" condition as he battles a recurrent lung infection, is receiving the best of care.
Mr Zuma got a briefing on Tuesday from doctors on the condition of the frail anti-apartheid icon, who has showed no sign of improvement after four days in hospital.
In a terse interview recorded earlier Tuesday, Mr Zuma said the 94-year-old father of modern South Africa was in a stable condition.
"We are all feeling it, that our president, the real father of democracy in South Africa, is in the hospital," Mr Zuma told public broadcaster SABC as Mandela was to spend a fifth day in hospital.
"We need him to be with us," Mr Zuma said. "And I'm sure, knowing him as I do, he's a good fighter and he'll be with us very soon."
Mr Zuma said he had full confidence in the medics attending to the former statesman, who was rushed to hospital in the early hours of Saturday.
"Whilst it is very serious... he's stabilized and we are all praying for him really to recuperate quickly," he said.
Mr Zuma's spokesman Mac Maharaj earlier told AFP that "stable has not meant better or worse, what it means is that his condition is not changing."
Mr Mandela's relatives streamed to the Mediclinic Heart Hospital in Pretoria to be at his bedside as fears grew over his condition.
Security was tightened around the private facility, where a dozen armed police stood guard outside and incoming vehicles and pedestrians were searched amid a heavy media presence.
A police sergeant told AFP that the officers had been deployed at the hospital "to protect the members of his family who come to visit him."
Mr Mandela's daughters Makaziwe and Zindzi, as well as former wife Winnie Madikizela-Mandela, were seen entering the hospital on Tuesday afternoon.
His current wife, Graca Machel, called off a trip to London last week to be with her ailing husband.
Tuesday marked 49 years to the day since Mandela was convicted in 1964 for conspiring to overthrow the apartheid government. A day later he was sentenced to life in prison.
He was sent to prison on wind-swept Robben Island, off the coast of Cape Town. He was later transferred to Pollsmoor Prison in Cape Town, where he contracted tuberculosis.
Jailed for 27 years for his beliefs, he became the undisputed face of the anti-apartheid struggle.
Mr Mandela's latest health scare has been met with a growing acceptance among South Africans that their hero, who became the first black leader of the country after historic all-race elections in 1994, may be nearing the end of his life.
He has a long history of lung problems since being diagnosed with early-stage tuberculosis in 1988. This is his fourth hospital stay since December.
Two months ago the Nobel peace laureate, who turns 95 next month, was discharged after treatment for pneumonia.
In December he underwent surgery to remove gallstones as he recovered from a lung infection. Then in March he was admitted for a scheduled overnight check-up before returning to hospital later that month for 10 days.
"Pneumonia is a killer disease," said Keertan Dheda, the head of pulmonology at the University of Cape Town.
"In Mr Mandela's case, besides age, we know that he has previously had tuberculosis and that can weaken the lung defences and make one more prone to infections."
'No longer the glue holding South Africa together'
In late April, Mr Zuma and top officials in the African National Congress, the anti-apartheid movement turned ruling party, were photographed with an unsmiling Mr Mandela looking exceedingly frail at his Johannesburg home.
The visit prompted allegations that the embattled party was exploiting Mr Mandela for political gain.
The ANC, facing 2014 elections, has lost much of its Mr Mandela shine amid widespread corruption, poverty and poor public services.
Mr Mandela has not been seen in public since the World Cup final in South Africa in July 2010, and has not been politically active for years.
"I think there will be concerns from outside South Africa that Mr Mandela is seen as the glue that holds South Africa together," analyst Daniel Silke told AFP.
"But I think that this is something long gone, frankly."
After serving just one term as president, Mr Mandela turned his energy to the battle against AIDS and to conflict resolution, before stepping out of the public eye at age 85.
Ordinary people, young and old, on Tuesday left messages of support outside his home in northern Johannesburg.
A couple wearing T-shirts bearing the words "We love you Papa Mandela" placed a teddy bear in a similar shirt outside the gate.
Others wrote messages of support on small stones outside the high security walls, while a group of schoolchildren stopped by to sing for him to "get well".