JOHANNESBURG, Dec. 10 -- World leaders and tens of thousands of South Africans on Tuesday gathered in rain at a stadium in South Africa's Johannesburg to honor former South African President Nelson Mandela.

Chinese Vice President Li Yuanchao, U.S. President Barack Obama, British Prime Minister David Cameron, Brazilian President Dilma Rousseff as well as U.N. Secretary General Ban Ki-moon were among the more than 90 leaders coming to honor the icon who died of lung trouble at the age of 95 at his house in Johannesburg on Dec. 5.

Mandela led the decades-long struggle against apartheid in South Africa. He was jailed for 27 years and released in 1990. Mandela became South Africa's first post-apartheid president in 1994. "Today we reflect on our memories of Nelson Rolihlahla Mandela," Cyril Ramaphosa, deputy president of South Africa's governing party ANC said when opening the service. "Today's memorial service should help each of us to gather our memories of Nelson Mandela."

Mandela could finally rest and enjoy the view of South Africa, he said. "His long walk has ended, but ours is just beginning," he said.

As a special representative of Chinese President Xi Jinping, Li expressed deep condolences and paid high tribute to former South African President Nelson Mandela, describing him as the pride of the African people.

"For all his life, he had strived for the liberation of African nations, championed the dignity of the African people and endeavored to advance the unity of all African countries and move forward Africa's cooperation with the world," Li said. He had dedicated his entire life to the development and progress of Africa, he added.

"Mr. Mandela had committed himself to China-South Africa friendship and China-Africa cooperation with great passion. The Chinese people will always cherish the memory of his significant contribution to China-South Africa friendship and China-Africa relations," he said.

He mentioned Mandela was an old friend of the Chinese people and a household name in China. "We are deeply saddened by the loss of such a great friend. At the same time, we are heartened to see that the cause Mr. Mandela had started will be carried forward," he said.

"We believe that under the leadership of President Zuma and the government of South Africa, the South African people will continue to make big strides forward along the path of national rejuvenation and development," he said.

"China stands ready to work with South Africa to deepen China- South Africa comprehensive strategic partnership, bring benefits to the two countries and two peoples, and make positive contribution to the noble cause of world peace and development," he said.

United Nation Secretary-General Ban Ki-moon said South Africa lost a hero, while the world lost one of its greatest teachers. "Mandela taught by example and was willing to give up everything he had for freedom and equality, for democracy and justice," he said.

He mentioned Nelson Mandela as one of the greatest leaders of time who made sacrifices for freedom, humanity, democracy and justice. "His compassion stands out most. He was angry at injustice, not individuals. He showed the awesome power of forgiveness," he said.

Obama who arrived late to the memorial service said Mandela "moved the nation towards justice."

South African President Jacob Zuma thanked international leaders for being in the country. He said everyone has had a Mandela moment. "This world icon has touched their lives," he said.

"Mandela brought us back on the road to freedom, the first South African elections were peaceful because of him," he said. "He is one of a kind, there is no-one quite like him," he said.

The rains since morning did not dampen the spirit of South African mourners singing and blowing trumpets in eulogy of Mandela. In the stadium flags were flying at half-mast and security was tight with a large contingent of police patrolling and standing on guard.

South Africa's Defense Minister Nosivewe Mapisa-Nqakula told the media that more than 11,000 troops were deployed, as well as a coordinated plan involving the military, air force and police.

"We are talking about Madiba here, so there is no margin for error," police spokesperson, Zweli Mnisi told ENCA news on Tuesday.

Susan Khupe, a young girl, walked 10 km to attend the service and came in early hours, trying to be "one of the early birds and avoid hassles at the gate."

"This is the biggest event ever to happen to South Africa. I have to pay my respect to our beloved hero, Nelson Mandela," said Khupe, wearing an African national Congress (ANC) T-shirt.

"South Africa will never be the same again. Rest in peace my hero, we love you!" said 46-year-old Soweto resident Timothy Nxumalo.

Some of the people at the stadium were carrying placards written: "We love you Tata, Mandela." However, the morning rains washed away some of the messages, but those that stubbornly remained told the stories of the life and death of Mandela.

Parents were bringing their children to remember Mandela. The children, born after the end of apartheid, said they were learning about him in school.

Peter Knox, a 10-year-old primary school boy, said he learnt a lot about Nelson Mandela in history lessons. "He was a gallant fighter, a revolutionary. His imprisonment at the Robin Island didn't prevent him from fighting the rights of the oppressed. I salute him," Knox said.