Nelson Mandela breathing without difficulty

The former president had fluid drained from his lungs, enabling him to breathe more easily

Nelson Mandela is 'responding to treatment' after returning to hospital with lung infection (Getty Images)

Nelson Mandela has is breathing without difficulty, according to the South African president's office.

He is spending a third day in hospital with a lung infection.

The statement from South African President Jacob Zuma's office said the national hero and Nobel peace laureate was comfortable and was continuing to respond to treatment.

The 94-year-old had fluid drained from his lungs, enabling him to breathe more easily.

There are no details yet on how long he will remain in hospital.

After Mr Mandela was admitted to hospital late on Wednesday, President Zuma said people "must not panic".

The former president first contracted tuberculosis during his stay in Robben Island prison. He is said to have damaged his lungs while working in a prison quarry. This latest spell in hospital is his fourth in just over two years.

Last December he was treated for a lung infection and gallstones - his longest period in hospital since leaving prison in 1990. In February, he was treated for a stomach condition.

Mr Mandela served as South Africa’s first black president from 1994 to 1999, after spending 27 years in prison for defying the Apartheid regime.

He has not been seen in public since the 2010 World Cup in South Africa. In the photographs and footage released annually on his birthday, he has always appeared to be in good spirits – but increasingly, as each year passes, frail.

The government refused to divulge the medical facility where Mr Mandela is being attended to, for fear of causing further anxiety.

Yesterday Mr Mandela's ex-wife, Winnie Madikizela-Mandela, told public broadcaster SABC on Friday that he was "doing well".

"He's responding very well to treatment," said Ms Madikizela-Mandela at a church service in Soweto.

When asked whether people should prepare for the inevitable, Mr Zuma said: "In Zulu, when someone passes away who is very old, people say he or she has gone home. I think those are some of the things we should be thinking about."

But he stressed that Mr Mandela had been able to handle the situation "very well" so far.