Nelson Mandela is back in hospital.

The former South African President & anti-apartheid leader, was admitted Saturday for a scheduled medical check-up. Doctors say there's no cause for "alarm", the president's office said.

A presidential spokesman Mac Maharaj says 94-year-old Mandela went in for tests "to manage existing conditions in line with his age".

In December, Mandela was hospitalized with a lung infection & had a surgical procedure to remove gallstones.