Nelson Mandela's home in South Africa, where the anti-apartheid icon has been receiving medical treatment since September, was a hub of activity Thursday as concern grew over his condition.
South African President Jacob Zuma's office was planning an "important announcement."
A tribal elder was seen at the Johannesburg home, and emergency vehicles were seen outside. Media and local residents were gathering outside.
The activity was unusual but there was no official word on whether his condition had changed.
Mandela, 95, spent three months in the hospital with a recurrent lung infection earlier this year but he was released in September.
Last month, Zuma said Mandela was in "stable but critical condition" was was continuing to respond to treatment.
Days earlier, his ex-wife, Winnie Madikizela-Mandela, had told South Africa's Sunday Independent newspaper, that he was “quite ill" and could not talk because of tubes in his mouth to clear fluid from his lungs.
"The bedroom there is like an ICU ward," the newspaper quoted her as saying, adding that Mandela used facial movements to communicate.
Mandela's lung problems have been attributed to the tuberculosis he contracted during his 27 years in prison, before he led his country to democracy and became its first black president.
He served for just five years but remains a figure of enormous moral influence in South Africa, where he is known to his countrymen simply as "Madiba."
A Nobel Peace Prize winner, Mandela retired from public life in 2004 with the half-joking directive, “Don’t call me, I’ll call you."