The government on Friday announced a five-day state mourning as a mark of respect to Nelson Mandela.

A decision to this effect was taken at a special meeting of the Union Cabinet, which condoled the death of the anti-apartheid icon.

"Mandela was the tallest leader of not only his generation but possibly this entire paradigm. The role that he personally played in dismantling the apartheid is something exemplary," information and broadcasting minister Manish Tewari said after the meeting.

A prisoner of conscience for over 20 years, the South African leader played an extremely vital role in giving a moral leadership to the world, he said.

"The entire nation is one with the South African people in condoling his sad demise.

"The Cabinet met today and passed a resolution condoling the death of Dr Nelson Mandela and it has been decided that there would be five days' state mourning...," he said.

A global symbol of resistance who liberated South Africa from much-despised apartheid regime and served as its first black president, Nelson Mandela died at his home in Johannesburg on Thursday after battling a protracted illness.

"Our beloved Nelson Rolihlahla Mandela, the founding President of our democratic nation, has departed," South Afrcian President Jacob Zuma said in a televised address to the nation, announcing the demise of the 95-year-old Nobel laureate.

Mandela, also a recipient of India's highest civilian award 'Bharat Ratna' in 1990, was receiving medical care from a team of doctors since September at his home in the suburb of Houghton here after spending three months in a Pretoria hospital for a recurrent lung ailment.

"Our nation has lost its greatest son. Our people have lost a father," he said.

"What made Nelson Mandela great was precisely what made him human. We saw in him what we seek in ourselves."

Zuma announced a state funeral for the elder statesman. Details of the funeral have not been announced yet, but all flags will fly at half-mast until the funeral.

He said Mandela's tireless struggle for freedom earned him the respect of the world: "His humility, his compassion, and his humanity earned him their love."

Hundreds of South Africans all over the country huddled in groups from the early hours of this morning to mourn the death of Mandela, who led the liberation of South Africa from white minority rule and served as its first black president.

Mandela, a lawyer and ex-boxer, spent 27 years in prison, most of them on Robben Island, after being convicted in the Rivonia trial with several others 50 years ago.

He stepped down in 1999 after serving one term as President following the first democratic elections in 1994.

As president, Mandela worked for uniting the polarised nation dominated by tribal politics. He devoted his energy to moderating the bitterness of his black electorate and to reassuring whites with fears of vengeance.

Mandela had been in and out of hospital for the past two years with a range of medical problems. His public appearances became rare but despite that he held a special place in the consciousness of the nation and the world.

US President Barack Obama mourned Mandela's death, saying "He no longer belongs to us -- he belongs to the ages."

"We've lost one of the most influential, courageous and profoundly good human beings that any of us will share time with on this Earth," Obama said.

UN Secretary-General Ban Ki-moon and the Security Council also mourned the death of Mandela, saying the South African leader was a "giant for justice".

"Nelson Mandela was a singular figure on the global stage - a man of quiet dignity and towering achievement, a giant for justice and a down-to-earth human inspiration. I am profoundly saddened by his passing," Ban said in his condolence message.

"On behalf of the United Nations, I extend my deepest condolences to the people of South Africa and especially to Nelson Mandela's family and loved ones," he said.

British Prime Minister David Cameron said, "One of the brightest lights of our world has gone out. Nelson Mandela was not just a hero of our time, but a hero of all time, the first president of a free South Africa, a man who suffered so much for freedom and justice."

The flag above Downing Street is flying at half-mast as a mark of respect, the BBC said.

China praised the former South African president as "an old friend of the Chinese people."

The South African government has set up a special tribute website at "http://www.mandela.gov.za"www.mandela.gov.za.

"Our thoughts are with the South African people who today mourn the loss of the one person who, more than any other, came to embody their sense of a common nationhood," Zuma said.

"Our thoughts are with the millions of people across the world who embraced Madiba as their own, and who saw his cause as their cause.

"Let us reaffirm his vision of a society in which none is exploited, oppressed or dispossessed by another. Let us commit ourselves to strive together ? sparing neither strength nor courage ? to build a united, non-racial, non-sexist, democratic and prosperous South Africa," Zuma added.

In his tribute to Mandela, Nobel laureate and Archbishop Emeritus Desmond Tutu said the former president had transcended race and class in his personal actions.

He said people cared about Mandela and loved him because of his courage, convictions and his caring ways for others.

"Mandela embodied and reflected our collective greatness. He embodied our hopes and our dreams. He symbolised our enormous potential, potential that has not always been fulfilled," Tutu said in a statement.