Former South African president Nelson Mandela has spent a fifth night in hospital to receive treatment for pneumonia.

A South African presidential spokesperson last night said the government had been advised by doctors that Mr Mandela had a "restful day" and continues to "make further progress".

Mac Maharaj said the government of President Jacob Zuma is "satisfied" that the doctors in Pretoria are providing the 94-year-old with the best treatment possible to assist his recovery and comfort.

The government earlier released a statement saying the anti-apartheid leader was breathing without difficulty after having a procedure to clear fluid from the area around one of his lungs.

Mr Zuma’s office said doctors were acting with extreme caution because of Mr Mandela's advanced age.

Mr Maharaj said President Zuma wanted to offer his thanks to South Africans and those throughout the world who had prayed for Mr Mandela and held him in their thoughts.

Mr Mandela was admitted to a hospital in the late hours of Wednesday evening.

It was his third trip to a hospital since December, when he was treated for a lung infection and also had a procedure to remove gallstones.

Earlier in March, he spent a night in a hospital for what officials said was a scheduled medical test.

Mr Mandela became South Africa's first black president in 1994 after elections were held, bringing an end to the system of white racist rule known as apartheid.

After his release from prison in 1990, Mr Mandela was widely credited with averting even greater bloodshed by helping the country in the transition to democratic rule.

The Nobel Peace Prize laureate has been particularly vulnerable to respiratory problems since contracting tuberculosis during his 27-year imprisonment for fighting white racist rule in his country.