South Africa's presidency says former leader Nelson Mandela is receiving treatment for a lung infection that has reoccurred.

In a Tuesday statement, a spokesman for President Jacob Zuma said doctors have concluded tests on Mr. Mandela that revealed the infection. The spokesman said the 94-year-old former president is “responding to the treatment.”

Mr. Mandela was admitted to a Pretoria hospital Saturday for what government officials said were tests “consistent with his age.”

He has grown frail and has not made a public appearance in several years. In February, Mr. Mandela was briefly hospitalized for abdominal pain.

He became South Africa's first black president in 1994. Prior to becoming president, he spent 27 years in prison for his fight against the country's apartheid policies.