The South African presidency has said that former president and anti-apartheid icon Nelson Mandela is still in "critical but stable condition".

The official statement came on Wednesday, as South African church leaders led prayers in front of the hospital where Mandela has spent two months in care.

After the prayers the president of the Council of Churches, Johannes Seoka, told journalists that - according to Mandela's wife Graca Machel - the ailing former president was responsive.

"We did not see Madiba, we prayed in a room reserved for visitors, for churches to come and pray where the family also receive Madiba's guests," he said, using Mandela's clan name.

"We were informed that he is critical but stable and that he is very conscious, he can hear every word that is spoken to him and he does respond."

Mandela, 95, was rushed to the Pretoria Mediclinic Heart Hospital on June 8 with a recurring lung infection.

His health has become a concern for South Africa's 53 million people, for whom Mandela remains a potent symbol of the struggle against decades of white-minority rule.

Although it has been relatively quiet outside the hospital where he is being treated, various family members have been visiting him daily.

South Africa's government has been secretive about Mandela's health, issuing infrequent and vague statements and declining to comment on the specifics of his condition.

Source: Agencies