As leaders walked into the venue, they were welcomed with screams, whistles and chants from the thousands of people who thronged the stadium to remember South Africa's most famous son, the South African Press Agency (SAPA) reported. (Agencies)
The atmosphere in the stadium is electric and it was hard to see anyone who was sitting down or not singing. Security is very tight around the venue and several streets around the stadium have been cordoned off.
Inside, bullet-proof screens have been erected around podiums where world leaders, including US President Barack Obama, will be seated. The delegation from India, a country that was very close to Mandela, is being led by President Pranab Mukherjee and includes Congress president Sonia Gandhi.
On Monday, State Security Minister Siyabonga Cwele sounded confident that South Africa was ready to handle the task of managing an unprecedented logistical challenge of hosting 91 world leaders.
The South African government has advised world leaders to attend the memorial service of Mandela in Johannesburg Tuesday instead of his burial ceremony in Qunu in the Eastern Cape province December 15.
"This is (in) view of the logistical challenges of hosting large delegations of VVIPs and VIPs in a village such as Qunu," a news agency quoted Collins Chabane, minister in the South African presidency, as saying.
According to SAPA, the gathering of world leaders for the memorial service has reportedly surpassed that for the 2005 funeral of Pope John Paul II, which was attended by 70 heads of state and 14 regional leaders. Among the high-profile guests attending Mandela's memorial service are heads of state and government and 10 former heads of state, the government confirmed on Monday.
This is perhaps an indication of the incredible influence and respect Mandela commanded from all corners of the world. World leaders remember Mandela's first appearance at the UN headquarters in New York, 23 years ago which many had said represented a beacon of hope for the oppressed.
"He was probably the greatest human being to ever live. We had them all, Diana (Princess of Wales) and Mother Teresa, but Mandela is in a league of his own," SAPA quoted visiting French journalist Antonio Batho as saying.
The memorial service programme will feature a series of tributes by some of the anti-apartheid icon's family and leaders, among them his comrade and fellow prisoner on Robben Island Andrew Mlangeni, and UN Secretary General Ban Ki-moon.
Obama, who is on his way to the stadium, is also scheduled to speak. Besides Sonia Gandhi, chairperson of the country's ruling United Progressive Alliance (UPA) alliance, the Indian delegation includes Leader of Opposition Sushma Swaraj, union Commerce and Industry Minister Anand Sharma, and members of parliament (MPs) Sitaram Yechury of the Communist Party of India-Marxist (CPI-M) and Satish Chandra Mishra of the Bahujan Samaj Party (BSP).
As leaders walked into the venue, they were welcomed with screams, whistles and chants from the thousands of people who thronged the stadium to remember South Africa's most famous son, the South African Press Agency (SAPA) reported.