Nelson Mandela in hospital for check-up

Mr Mandela was hospitalised for nearly three weeks in December (AFP)

Nelson Mandela, the former South African president and anti-apartheid leader, was admitted to a hospital in Pretoria yesterday for a scheduled medical check-up. Doctors say there is "no cause for alarm".

Officials have used similarly soothing language to explain previous hospital stays for the 94-year-old, but in those cases it turned out that he had more serious conditions.

The intense privacy surrounding the health of Mr Mandela reflects in part the official reverence for a man who is seen as one of the great, unifying figures of the 20th century – helping to avert race-driven chaos in South Africa's tense transition from apartheid to democracy.

Mr Mandela was hospitalised for nearly three weeks in December. At that time, he was treated for a lung infection and had a surgical procedure to remove gallstones.