Zuma says Mandela 'glue' holding South Africa together

The leader of South Africa's ruling party said former President Nelson Mandela was the glue holding the country together, giving voice to long-held fears about the future of the fledgling democracy without him.

Jacob Zuma joined 500 guests, including President Thabo Mbeki and former Zambian leader Kenneth Kaunda, in birthday celebrations for Mandela on Saturday.

Mandela turned 90 on Friday, more than 14 years after becoming the country's first black president at the end of white minority rule.

"You are the glue that holds us together as a nation. You provide eternal hope in our people and the world that South Africa can only be a better place each day," Zuma said in a speech delivered at Mandela's rural home at Qunu in the Eastern Cape province.

Mandela, who spent 27 years in jail for his anti-apartheid activities, became a symbol of unity between black and white South Africans during his one term as president, but the euphoria that accompanied those early years has somewhat faded.

Although Mandela has long retired from active politics, many say he still provides a unifying force in a country where divisions between black and white, as well as rich and poor are resurfacing as a largely black majority stays mired in poverty.

Financial Mail editor Barney Mthombothi wrote in a tribute to Mandela on Friday: "We're approaching a future without his commanding presence with some trepidation. . We won't see the likes of him again."

Critics say Mandela's successor Mbeki has failed to address the huge gulf between rich and poor which is stoking labour unrest, while South Africa still suffers one of the world's worst crime rates.

Mbeki lost the leadership of the ANC to Zuma in a bruising battle last December which exposed divisions within the ruling party.

But on Saturday Mbeki and Zuma put aside their differences and joined celebrations for Mandela, which included performances by choirs and dancers, while cattle herders beat drums outside.

Tributes to Mandela continued pouring in, including from U.S. presidential candidate Barack Obama, who is trying to make history in November by becoming the first black U.S. president.

"Celebrations and simple words of admiration are not enough . to honour a man who's brought hope to a world often filled with despair; who's brought so much love to a world so filled with hate and who's shown us how much we can achieve when we have the courage to be our better selves," Obama said in a message.

"No, the way to truly honour you, Nelson Mandela, is to act each and every day in our own lives to do our part for our fellow human beings and to live up to the example you continue to set each and every day," he added.