HARARE -- Zimbabwe's aging President Robert Mugabe, who turns 90 next month, said at his sister's funeral Tuesday that his longevity is "the grace of God".

Mugabe's appearance at the burial of Bridget, 79, at the family 's rural home of Zvimba, nearly 100 km from Harare, also marked his first public appearance in weeks, ending the speculation that the veteran leader was seriously ill, or even had died.

Mugabe, who has ruled Zimbabwe since its independence in 1980, usually takes his weeks-long annual leave in January. He has repeatedly denied unverified claims that he suffers from prostate cancer. Now Africa's oldest head of state, Mugabe is said to have had only minor eye problems. He was operated twice to remove cataract in Singapore in his late 80s.

"Do not ask, how come you have lived this long yet you are older? I do not know how I have lived this long, it is all in God' s hands," he told mourners gathering in Zvima for the burial in an hour-long speech spiced by jokes and anecdote.

After Bridget died, Mugabe becomes the only survivor among his six siblings. Bridget died of heart failure last Sunday after slumping into coma three and a half years ago.