World leaders, civilians and celebrities alike took time off their busy schedules on Saturday to pay tribute to the father of the South African nation on his 91st birthday, the South African Press Association reported.

South Africa Former President Nelson Mandela blows out candles next to his wife Graca Machel on his 91st birthday at his home in Johannesburg July 18, 2009. [Xinhuanet.com]

South African President Jacob Zuma, deputy president Kgalema Motlanthe, former president Thabo Mbeki, former Zambian president Kenneth Kaunda and former U.S. president Bill Clinton were among the leaders who paid tribute to Nelson Mandela by dedicating 67 minutes to community work.

"He loved even those who persecuted him. Even when he was released after 27 years, he taught reconciliation and forgiveness," said Zuma as he addressed the elderly at an old-age home in Ivory Park.

"He taught that the only way to achieve personal freedom was to release hatred from your heart."

Earlier, Zuma was one of the visitors at Mandela's Houghton home, which was also packed outside with journalists.

The Nelson Mandela Foundation (NMF) said more than 90 people visited him at home, including Kaunda, various members of the ANC National Executive Committee, Mandela's wife Grace Machel and his former wife Winnie Madikizela-Mandela and grandchildren.

"He received a standing ovation from politicians who sang happy birthday to him," the foundation said.

"Madiba blew out the ten gold candles on his cake in the ANC colours of black, green and gold. The cake was shaped in the numbers 91.

"Written on it were the words, 'Long Live Madiba', written in chocolate icing," the foundation said.

Former South African President Nelson Mandela (L) and current President Jacob Zuma celebrate Mandela's 91st birthday at his home in Johannesburg July 18, 2009. [Xinhuanet.com]

Mandela ate a piece of cake offered to him by his eight-year- old grandson Ziyanda Manaway.

Speaking at the Houghton gathering, Zuma said it was a blessing from God that Madiba was still alive at his age.

"Sit at home as a pensioner and have no worries that the ANC is in good hands. We will follow your example forever," Zuma assured Mandela.

At the Nelson Mandela Day celebration in Newtown, Johannesburg on Saturday afternoon, Motlanthe called on all South Africans to emulate Mandela's humility and vision.

He added that if people failed Madiba, it was a betrayal and a crime against history.

"Madiba has made the world a better place. Let us emulate his confidence, his humility, his determination, his strength and his vision," Motlanthe said.

Former Zambian president Kenneth Kaunda described Madiba as a "God-send".

"He is God's messenger. He truly loved his neighbour as he loved himself. A truly remarkable man he is."

Former president Thabo Mbeki also praised Mandela, saying he was an inspiration towards completing the work still needed to be done in South Africa.

"Really what needs to be done is ensuring that we continue very firmly and very steadily on the path towards a better life for the people in conditions of stability for the country, in conditions of unity for the people of South Africa."

Former U.S. president Bill Clinton also paid tribute to Mandela in New York by raising funds at a gala dinner. The proceeds were to go to charities in the area.

New York was also hosting a star-studded concert in honour of Madiba with performers including Stevie Wonder, Alicia Keyes and the Soweto Gospel Choir.

A Cape Town resident stands beside a poster of former President Nelson Mandela as he takes part in Mandela's 91st birthday celebrations July 18, 2009.[Xinhuanet.com]

Speaking from the city, NMF chief executive Achmat Dangor said Mandela was healthy at 91-years-old.

"He is so vigorous for his age," Dangor said, on SABC television.

And while politicians paid tribute to the world's greatest living icon, so too did the people whom he served.

South Africans planned to spend Saturday sprucing up neglected schools, painting vandalised walls, distributing food parcels and blankets, and even reading newspapers to the elderly.

Others expressed their well wishes to Madiba by sending cellphone text messages to news channels and media houses.

By midday, the SABC had received 11,000 birthday messages for Madiba.

Meanwhile, NMF which is at the forefront of the birthday celebrations, raked in 2.2 million rand (270,000 U.S. dollars) in fund-raising.

Even at Mandela's rural village Qunu near Mthatha in the Eastern Cape, celebrations continued. Buses continued to arrive with traditional dancers from around the country to show off their performances.

(Xinhua News Agency July 19, 2009)