Nelson Mandela Undergoes Successful Procedure : Gallstones Removed.

Nelson Mandela is recovering from a successful operation to have gallstones removed, the South African government has confirmed.

"The former president underwent a procedure via endoscopy to have the gallstones removed ... The procedure was successful and Madiba is recovering," the government statement said, referring to Mr Mandela by his clan name.

Mr Mandela was admitted to the Military Hospital in Pretoria on December 8 for tests, which revealed the recurrence of the infection. Doctors wanted to treat him for this first before carrying out the gallstones procedure, the government said.

Mr Mandela's latest hospital stay has caused growing concern in South Africa, which idolises him as the nation's first democratically-elected president after the apartheid era. He made his last public appearance when his country hosted the 2010 World Cup football tournament.

South African President Jacob Zuma has wished Mr Mandela a "speedy recovery".