JOHANNESBURG (AP) — Military doctors are treating South Africa's former President Nelson Mandela for a recurring lung infection, an ailment the 94-year-old anti-apartheid leader remains susceptible to because of his age and his 27 years in prison.

Government officials acknowledged for the first time Tuesday that the illness forced soldiers to admit Mandela to a military hospital on Saturday, though they said politician was responding to treatment.

Mandela fought off a similar infection in 2011 and has a history of tuberculosis. Medical experts say respiratory illnesses like pneumonia striking a man his age are a serious matter that require care and monitoring.