Former South African president Nelson Mandela has spent a second night in hospital in Johannesburg, as fears grow for his health.
The office of the anti-apartheid campaigner says the hospital visit is for routine tests.
But that has not stopped concern in the country and overseas for the 92-year-old, who has not been seen in public since the FIFA World Cup closing ceremony last July.
There has been growing anxiety about the Mr Mandela's health after he spent a second night in Milpak Hospital.
Since Wednesday he has reported to have been undergoing routine tests.
The BBC reports it is believed the statesman is being treated for a lung condition, but no clear medical condition has been released.
Some reports suggest he has suffered a collapsed lung, but this has not been confirmed.
South African president Jacob Zuma, who is in Switzerland for the World Economic Forum, has issued a plea for the nation to remain calm.
A statement from the presidency sough to give some reassurance. It said that Mr Mandela was in high spirits and has been visited by family and friends and there was no need to panic.
Mr Mandela - known affectionately among South Africans by his clan name Madiba - has appeared increasingly frail on his infrequent public appearances since retiring from public life in 2004.
Nobel Peace Prize winner Archbishop Desmond Tutu on Thursday said Mr Mandela was "frail" when he saw him last week, the SAPA news agency reported.