Former South African president Nelson Mandela remained in a critical but stable condition and was responding to treatment, President Jacob Zuma said after visiting the anti-apartheid hero in a Pretoria hospital.
Mandela, whose 95th birthday is on July 18, has been receiving treatment for a recurring lung infection that has led to four hospital stays in the past six months.
Several of Mandela's comrades in the anti-apartheid struggle gathered at Liliesleaf Farm outside of Johannesburg on Thursday to mark the 50th anniversary of a police raid that led to their arrests, which dealt a heavy blow in the battle to end white-minority rule.
Mandela had been in jail for a separate conviction at the time of the farm raid but was named as "accused number one" in a conspiracy plot when those arrested at Liliesleaf were brought to court in what is known as the Rivonia Trial.
Mandela had previously evaded apartheid police by posing as a caretaker and hiding out at Liliesleaf.
Many of Mandela's comrades lamented the precarious state of the man who was a giant in the struggle.
"It's a sad coincidence that he can't be with us and that he is in hospital today," said Bob Hepple, who was initially charged of plotting with Mandela to overthrow the apartheid regime.
Mandela and several others were found guilty and sentenced to life in prison. They later won their release and struck a deal that brought about all-race elections in 1994 that ended apartheid
Mandela has spent more than a month in hospital. His eldest daughter Makaziwe said in a court document filed in June that her father was breathing with the aid of life-support machines.
The failing health of South Africa's first black president, a figure admired globally as a symbol of struggle against injustice, has reinforced a realisation that the father of the post-apartheid state will not be around forever.