JOHANNESBURG, South Africa -- The memorial service for former South African President Nelson Mandela on Tuesday is poised to be one of the largest such gatherings in generations with tens of thousands of local mourners and dozens of foreign leaders expected.

South African officials say the normal seating capacity of Johannesburg's FNB stadium probably won't suffice to accommodate all mourners. Security for the event is likely to be tight as the list of presidents, heads of government, royalty and celebrities keeps growing by the hour.

The South African government said Sunday a total of 53 heads of state, government and ministers have confirmed they will be attending the service.

Here's a selection of confirmed attendees compiled by The Associated Press:

  • U.S. President Barack Obama and first lady Michelle Obama as well as former presidents George W. Bush, Bill Clinton and Jimmy Carter.
  • UN Secretary General Ban Ki-moon and his predecessor Kofi Annan.
  • British Prime Minister David Cameron.
  • French President Francois Hollande.
  • Canadian Prime Minister Stephen Harper and three of his predecessors.
  • German President Joachim Gauck.
  • Spanish Prime Minister Mariano Rajoy and Prince Felipe.
  • Brazilian President Dilma Rouseff and three of her predecessors, including Luiz Inacio Lula da Silva.
  • Indian President Pranab Mukherjee.
  • Australian Prime Minister Tony Abbott.
  • The Netherlands' Foreign Minister Frans Timmermans and King Willem-Alexander.
  • Danish Prime Minister Helle Thorning-Schmidt.
  • Norwegian Prime Minister Erna Solberg and Crown Prince Haakon.
  • Czech Foreign Minister Jan Kohout.
  • European Union Council President Herman Van Rompuy.
  • Haiti's Prime Minister Laurent Lamothe.
  • Nepal's Foreign Minister Madhav Prasad Ghimire.
  • Sri Lanka's President Mahinda Rajapaksa.
  • Bangladesh's President Abdul Hamid.
  •  Former Finnish President Martti Ahtisaari and former Irish head of state Mary Robinson as part of the delegation of The Elders, a group of former statesmen which Mandela helped to launch.
  • British entrepreneur Richard Branson and singer Peter Gabriel, who brought the idea of The Elders to Mandela.