The death of Ghana's President John Evans Atta Mills left the nation in shock. Mills was months away from completing his first term in office.
Crowds gathered at the 37 Military Hospital in the capital, Accra, in a mass outpouring of grief in the West African nation.
The news follows weeks of speculation about his health after a decline in public appearances and a trip to the United States for medical reasons, which the president insisted was a "routine check-up".
Mills's death was announced publicly on Tuesday afternoon after hours of rumours and a near communications blackout in Accra.
A statement from the office of the president said: "It is with a heavy heart that we announce the sudden and untimely death of the president of the republic of Ghana."
MPs were summoned to the Parliament in Accra for the swearing-in of the vice-president, John Dramani Mahama, amid reassurances that Mills's death would not spark a constitutional crisis.
But there were questions about how his death, the first of a serving president in Ghana's 55 years as an independent nation, would affect elections due to take place in December.
Mills, who had begun campaigning for re-election for the ruling National Democratic Congress party, was expected to fight a narrow contest against the opposition National Patriotic Party.
Earlier this month Mahama published a memoir, My First Coup d'Etat and Other True Stories from the Lost Decades of Africa.
It has been described as a coming-of-age account set during Ghana's post-independence years. – © Guardian News and Media Limited 2012.