PRETORIA (AFP) - Two South African businessmen on Tuesday released 100 white doves into the air outside the hospital where anti-apartheid icon Nelson Mandela is fighting for his life.

"It symbolises that fact the we need to have love as South Africans, we need to have peace in South Africa," well-wisher Thomas Toutts told AFP.

Flowers, balloons and messages of support piled up outside the Pretoria hospital where 94-year-old Mandela was admitted on June 8 with a recurrent lung infection.

"We feel this is the right place, where our father of the nation is lying in hospital," said Mr Toutts, a tax consultant and events manager who also breeds doves.

His business partner Calvern Hugo said their gesture was to recognise Mandela's contribution to the country's freedom.

"We are really appreciative of what you have done for us as a nation. What you have done will echo throughout the generations to come," he said, in words intended for the elderly statesman.

The Nobel Peace Prize winner spent 27 years behind bars for his struggle under white minority rule and went on to become South Africa's first black president.

Mr Mandela's condition appeared to take a significant turn for the worse over the weekend with the presidency announcing on Sunday that he was "critical".

One of his granddaughters, Ms Ndileka, told AFP on Tuesday that Mr Mandela's condition was "stable".

His lung problem dates back to his time breaking rocks at the windswept Robben Island prison camp near Cape Town.