Malawi's President Bingu wa Mutharika was unconscious in hospital after suffering a heart attack Thursday, amid mounting discontent with his leadership and demands for his resignation.
State radio said the 78-year-old president, who is in critical condition, would be airlifted to South Africa for specialist treatment later Thursday, as officials called for the people of Malawi to pray for his recovery.
A senior official at Kamuzu Central Hospital in the political capital Lilongwe said Mutharika collapsed at his official residence and was rushed to the hospital where he is being treated in an intensive care unit.
"He had a cardiac arrest, he is still unconscious since 9:00 am (0700 GMT)," the official said on condition of anonymity, describing his condition as critical.
Mutharika has been visited by senior politicians from his cabinet, as well as his wife and children, hospital sources said.
"When I first heard the state president had been taken ill, I quickly wished him quick recovery," said Vice President Joyce Banda, who is currently at odds with Mutharika.
"I wish to ask all Malawians to pray for the quick recovery of our state president," said Banda, who fell out of favour with the president a year after being elected as his running mate in 2009.
She was the first official to make any announcement about the president's health, and earlier state media had not broadcast any news about his condition in an information blackout that lasted most of the day.
But later state radio said he would be flown to South Africa "to receive further specialist attention".
South African foreign affairs spokesman Clayson Monyela declined to comment on Mutharika's treatment in the country.
The constitution stipulates that the vice president assume executive power in the president's absence, but it's not yet clear if that will happen given the tensions between Mutharika and Banda, who was kicked out of the ruling Democratic Progressive Party (DPP) in 2010.
The president had also apparently been grooming his brother, foreign minister Peter Mutharika, as a successor.
Mutharika, a former World Bank economist who first came to power in 2004, was re-elected with a sweeping majority in 2009 as president of the poor southern African country.
But his second term has been marred by anti-government protests, with activists accusing him of mismanaging the economy and trampling on democratic freedoms.
Two weeks ago he vowed to govern until his term ends in 2014 after a leading rights group threatened unrest if he did not resign or call a referendum on his leadership.
"I would like to say that Bingu doesn't run away from work, Bingu doesn't desert responsibility even if the going gets tough," the president told a rally.
Last month, the Public Affairs Committee (PAC), made up of religious groups, rights activists and the opposition, demanded that Mutharika quit office or call the referendum within three months.
The group accused him of mismanaging the economy and trampling on democratic freedoms, saying the country was on the brink of becoming a failed state.
Critics have lambasted new laws to restrain the media, limit protests, and restrict lawsuits against the government.
Political tensions erupted into rioting in July, when police shot 19 people dead.
Ahead of the riots, alarmed by his restrictions on political freedoms, donors had already begun suspending aid, with former colonial power Britain slashing its financial support.
The leader presided over steady economic growth but has struggled to manage foreign currency reserves, which have also been hit by a drop in earnings from the country's main export tobacco.
His refusal to listen to criticism, whether from civil society or the International Monetary Fund, has earned him the moniker "Mr Know-it-All".