Children hold balloons and flowers as they gather to wish to former President Nelson Mandela happy birthday.

Children hold placards as they gather to wish to former President Nelson Mandela happy birthday at a township school in Atteridgeville near Pretoria.

A woman stands in front of posters and get well messages outside the Medi-Clinic Heart Hospital, where the ailing Mandela is being treated, in Pretoria.

Children hold flags as they gather to wish former President Nelson Mandela happy birthday outside the Medi-Clinic Heart Hospital, where he is being treated, in Pretoria.

Nelson Mandela celebrated his 95th birthday in hospital showered by tributes from around the world.

Thousands of South Africans led the global outpouring of support for the man regarded as the father of the multiracial 'Rainbow Nation" established in 1994 when he was elected its first black president at the end of apartheid.

He has been receiving intensive treatment since June 8 for a recurring lung infection, his fourth stay in hospital in six months.

While many carried out volunteer work on U.N.-declared Nelson Mandela Day, his daughter Zindzi led government workers in singing "Happy Birthday" to the Nobel Peace Prize laureate, one of numerous celebrations across the country.

"His doctors have confirmed that his health is steadily improving," President Jacob Zuma's office said in a statement.

"On behalf of government and all the people of South Africa, we wish Madiba a joyous 95th birthday," it said using Mandela's traditional clan name.

The fragile health of Mandela, who for weeks has been in a critical condition, has served as a reminder of the mortality of the man globally admired as a symbol of struggle against injustice and of racial reconciliation.

Many in South Africa celebrated Mandela Day with 67 minutes of public service to honour the 67 years Mandela served humanity by first fighting against white-minority rule and then consolidating racial harmony when he was president.

His former wife Winnie Madikizela-Mandela called the 95th birthday "a gift to the nation".

"There are some prophets of doom who say the country will come to a standstill (when he dies)," she told Talk Radio 702.

"The country will continue as it has always done. If anything, the country will solidify, come together and carry on."

GLOBAL CELEBRATION

Across South Africa, office workers, students, soldiers and ordinary citizens marked Mandela Day by sprucing up orphanages, painting walls at schools and delivering food to the poor.

The United Nations declared July 18 as Nelson Mandela International Day in 2009 and will celebrate with speeches from figures such as former U.S. President Bill Clinton.

Mandela Day will be marked in nearly 20 U.S. cities with commemorations around Capitol Hill in Washington, DC and by volunteers handing out South African oranges in New York.

"Nelson Mandela is synonymous with the reputation and the good name of this country. He is one of those iconic figures who has come to represent not only what South Africa stands for but what we as a country are trying to contribute to the world," said Miller Matola, chief executive of Brand South Africa.

Mandela's victory in the first multiracial elections in 1994 put an end to the apartheid system. Four years earlier, he was released from 27 years spent in prison under white minority rule, 18 of them at the notorious Robben Island penal colony.

"Tata (our father) is making this remarkable progress and we look forward to having him back home soon," Zindzi said at an event where she received his newly revised government ID card.

Zindzi said the family planned to give Mandela a collage of family photographs for a present and have lunch together at the hospital where their patriarch is being treated.

Reuters