Meanwhile, Malawi's ex-leader Bakili Muluzi on Friday called for "constititional order" after the death of President Bingu wa Mutharika, saying the vice president must automatically take power.
"I am calling for a constitutional order, for continued peace and order. The laws of Malawi are very clear that the vice president takes over" when the sitting president can no longer govern, Muluzi told a news conference.
"We have to avoid a situation where there is disorder. Let us follow the constituion. We have no choice but follow the constitution. It's very important that there must be peace and calm," he said at his home outside the commercial hub Blantyre.
Hospital and political sources have confirmed that Mutharika died following a heart attack Thursday, but most ordinary Malawians have yet to receive the news due to an official silence in the state media.
"It's important that the government announces the condition of the president as soon as possible so that the nation is informed," Muluzi said.
Mutharika had been trying to force Vice President Joyce Banda from office, after he expelled her from the ruling party in 2010. She since formed her own party and emerged as one of Mutharika's toughest critics. AFP