JOHANNESBURG — Nelson Mandela is spending a thirteenth day in a South African hospital after being diagnosed with a lung infection and undergoing gallstone surgery.

Presidential spokesman Mac Maharaj said Thursday that there is no update on the medical status of the anti-apartheid icon, who was admitted Dec. 8 to a hospital in the capital, Pretoria.

On Tuesday, President Jacob Zuma said 94-year-old Mandela required "extraordinary care" due to his age and could spend several more days in the hospital recovering.

Mandela was a leader of the struggle against racist white rule in South Africa, serving 27 years in prison for his beliefs. He served one five-year term as president before retiring from public life.