Doctor: Madiba's procedure was minor

A doctor says the procedure Nelson Mandela underwent to remove gallstones was minor.

Nelson Mandela.

JOHANNESBURG - Former President Nelson Mandela on Monday spent a tenth night in a Pretoria hospital after being treated for a lung infection and undergoing a procedure for gallstones.

The 94-year-old was flown to a Pretoria hospital from his home in Qunu in the Eastern Cape for what was initially only treatment for a recurring lung infection.

On Saturday the presidency revealed he also underwent endoscopic surgery to remove gallstones.

Doctor Mark Sonderup said this was usually a less invasive procedure.

"It is a procedure done in contrast to doing a full operation. It is even less invasive than keyhole surgery because it's done through a pipe, through your stomach. It can be done under light sedation or light anesthesia."

It remains unclear when Madiba will be discharged.