World leaders to honour Mandela

South Africa on Saturday began preparations to host US President Barack Obama and other world leaders eager to pay their respects to Nelson Mandela during 10 days of mourning for the anti-apartheid icon.

On Friday President Jacob Zuma announced the mourning period for Mandela, the founding father of modern South Africa and its first black leader, after he died late Thursday aged 95, surrounded by friends and family.

Obama, America's first black president, will travel to South Africa next week, the White House said, joining a raft of world leaders for a huge December 10 memorial service.

Mandela's body will lie in state in Pretoria for three days before he receives a state burial on December 15 in his boyhood home of Qunu.

The logistics are daunting for hosting the great and the good who plan to fly in from around world to honour the universally respected statesman.

The travel industry expect accommodation in Johannesburg and Pretoria to be sold out as the South African government and various consulates block book hotel rooms.

Memorial events begin Sunday with South Africans invited to visit churches, mosques, synagogues and other places of worship, to pay their respects.

Obama and his wife Michelle will travel to South Africa together with former first couple George W. and Laura Bush.

Ex-president Bill Clinton, who was in office when Mandela took power to become South Africa's first black president, also said that he would be making the trip with his family.

White House press secretary Jay Carney said the Obamas would "participate in memorial events" without giving details.

In a tribute shortly after the revered statesman's death was made public, Obama mourned Mandela as a "profoundly good" man who "took history in his hands and bent the arc of the moral universe towards justice".

Brazilian President Dilma Rousseff will also be among those flying in next week, her office said.

On Friday, ordinary South Africans across the country poured out onto the streets in a riot of colour, dance and song to celebrate the life of their beloved ex-leader, known affectionately as Madiba.

In Cape Town, a crowd of thousands from all races and ages gathered for a multi-faith celebration at the site where Mandela made his first public speech after nearly three decades in apartheid jail.

"Tonight we stand in solidarity as the people of Cape Town -- black, white, coloured, Indian, all the religions together," said mayor Patricia De Lille.

South Africa's archbishop emeritus Desmond Tutu, a fellow Nobel prize winner, praised Mandela as an "incredible gift that God gave us".

Fighting back tears, Tutu said his old friend was "a unifier from the moment he walked out of prison".

Mandela spent 27 years in an apartheid prison before becoming president and unifying his country with a message of reconciliation after the end of white minority rule. He shared the Nobel Peace Prize with South Africa's last white president, F.W. de Klerk, in 1993.

Palestinians and Israelis, Beijing and the Dalai Lama, Washington and Tehran all paid heartfelt tribute to Mandela, describing him as one of the towering figures of the 20th century who inspired young and old with his fight for equality.

North Korea, in its first official reaction on Saturday, sent its condolences to South Africa, praising Mandela's "struggle against racism and for democracy".

Zimbabwe's President Robert Mugabe paid tribute to Mandela as "a champion of the oppressed".

Even Syria's beleaguered president, Bashar al-Assad, ventured a homage on his official Facebook page, calling Mandela "a torch for the resistance and liberation from racism, hatred, occupation and injustice."

Flags flew at half-mast in numerous countries, including the United States, France and Britain, and at the United Nations headquarters in New York.

New York's Empire State Building and Paris' Eiffel Tower were lit up in the colours of the South African flag.

India declared five days of mourning for a man the premier labelled "a true Gandhian".

And a Paris summit of some 40 African leaders was overshadowed by Mandela's death. An old associate, African Union Commission president Nkosazana Dlamini Zuma, said Mandela "was a son who became larger than the continent".

South African Foreign Minister Maite Nkoana-Mashabane said the best way to remember Mandela was to free the African continent of poverty, unrest and disease.

"We will do it in your name," she said.

In Brazil, organisers of the 2014 football World Cup flashed Mandela's image up on a giant screen and held a minute's silence before the groups' draw.

Family 'overwhelmed' by support

Mandela had waged a long battle against a recurring lung infection and had been receiving treatment at home since September following a lengthy hospital stay.

Mandela's two youngest daughters were in London watching the premiere of his biopic "Long Walk to Freedom", along with Britain's Prince William, when they learned of his death.

British actor Idris Elba, who portrayed Mandela in the film, said: "We have lost one of the greatest human beings to have walked this Earth."

Mandela's eldest grandson Mandla expressed gratitude for the international outpouring of support, saying the messages had "heartened and overwhelmed" the family.

Outside his house in the upmarket Houghton suburb and at his former residence in the once blacks-only township of Soweto, scores of well-wishers danced and sang old songs of struggle to celebrate Madiba.

His December 10 memorial service will take place in a 90,000-plus capacity Soweto stadium.

Once considered a terrorist by the United States and Britain for his support of violence against the apartheid regime, at the time of his death Mandela was an almost unimpeachable moral icon.