Eyewitness News has independently verified that the former president is now on life support.

PRETORIA - Former President Nelson Mandela's granddaughter Ndileka has told reporters at the Mediclinic Heart Hospital that Madiba remains in a critical condition, but is stable.

She and several other relatives collected flowers and messages of support which have been pinned to what has become a tribute wall to her grandfather.

Several members of the Mandela family arrived at the Mediclinic Heart Hospital in Pretoria amid reports that they were summoned there.

Eyewitness News has independently verified that the former president is now on life support.

Ndileka thanked South Africans for supporting the family and praying with them during this difficult time.

"We're anxious as you know he's critical but he's in a stable condition right now."

She says there is tremendous strain on the family, particularly because of the media focus.

"It has been hard especially because of doing everything in the public eye."

But Ndileka said they're heartened by the outpouring of support.

"There's a lot of comfort that's coming from the messages."

The latest developments about Madiba's health have left the nation, if not the world on edge.

'MADIBA'S FATE IN THE HANDS OF GOD '

President Jacob Zuma has also cancelled a trip to Mozambique for a SADC summit meeting after visiting the ailing statesman on Wednesday night.

The Presidency says the 94-year-old's medical team is doing everything it can to ensure his well-being at this stage.

Spokesperson Mac Maharaj said, "In the meantime President Zuma has reiterated his thanks to all South Africans for the support they're giving to the Mandela family."

Traditional leader and ANC MP Phathekile Holomisa says the Mandela family are hoping for a "miracle".

Holomisa said Madiba's fate is now in God's hands.

"The Mandela family wish a miracle would happen that he recovers, but at the same time they are aware that there's a limit to the miracles you can have."

Meanwhile, officials with US President Barack Obama on his three-nation African safari are indicating that the programme for the South African leg which begins on Friday will change radically or even be scrapped should Mandela's condition change.

US embassy sources in Pretoria say Mandela is in their thoughts and prayers and they're pushing ahead with arrangements for the visit.

OVERWHELMING SUPPORT

Minister in the Presidency Trevor Manuel has added his voice to scores of people reflecting on Mandela's legacy.

He says it is important to reflect on Madiba's brave and bold character, by not only making sure South Africa achieves democracy but ensuring that it is a success.

"Right now as he is lying ill and beyond this, we need to focus on continuing his legacy and it must live on in all of us. Each South African needs to be 'Mandela' - live the values and live in service.

It's 20 days since Madiba was admitted for a recurring lung infection and this week has seen more messages of support outside the hospital and his Houghton home with many of the well-wishers holding out hoping that the 94 year old will recover.

Almost three weeks ago it was just a few coloured stones covering Madiba's lawn with messages of support for him.

In stark contrast on Wednesday several visitors left personalised letters in sealed envelopes, posters and flowers outside his home.

A woman came all the way from Dubai to drop off a tribute flag and came along with her two sons.

Meanwhile, messages continue to pour in outside the facility and the Salvation Army has joined several organisations and hundreds of South Africans who've paid tribute to the former president.

While the Salvation Army sang hymns, its members placed flowers at the tribute wall outside the hospital.

The organisation's William Langa said Madiba will always be remembered.

"Let us hold on and look high, retire the banner and move forward."

The DA's Mmusi Maimane was also there to place flowers.

"We pray for his comfort and peace and his family during this time."

Comedian Trevor Noah, who's currently performing in New York, says we should celebrate Madiba's legacy.

"I can understand people are sad but the truth is we're more afraid of him passing than he is. He's somebody's grandfather now and not our guy, his legacy is ours and that's what we should focus on keeping that alive."

QUNU YOUTH CAMP WITH A DIFFERENCE

Facilitators of a winter youth camp at the Nelson Mandela Museum in Qunu are hoping his leadership qualities and life will inspire young people from the Eastern Cape.

Dozens of pupils between the ages of 14 and 18 have been chosen to take part in the camp at a youth and heritage centre on the museum grounds.

School pupils here have been channelling their energy into activities such as poetry, art and drama.

Youth facilitator Vusani Nesengani said, "The attributes which Madiba has are being instilled into the children so they can become future leaders."

A pupil said Mandela inspired many generations.

"We're the Madiba generation and we need to enhance his legacy."