JOHANNESBURG (AP) — Nelson Mandela remains hospitalized in South Africa for an eleventh day after undergoing surgery and receiving treatment for a lung infection.

South Africa’s government has said the 94-year-old Mandela was admitted Dec. 8 to a hospital in the country’s capital, Pretoria. Officials said Mandela underwent an endoscopic surgery to remove gallstones Saturday after doctors treated him for a recurrent lung infection.

Presidential spokesman Mac Maharaj, who has issued statements previously about Mandela’s health, did not respond to requests for comment Tuesday from The Associated Press. 

Mandela is revered for being 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.