Madagascar's new military ruler Colonel Michael Randrianirina will be sworn in as president in coming days, two sources familiar with the matter said on Wednesday, after a coup he led to oust President Andry Rajoelina.

Rajoelina, who was impeached by lawmakers on Tuesday two days after fleeing the Indian Ocean island, condemned the takeover and has refused to step down despite escalating Gen Z demonstrations demanding his resignation and widespread defections in security forces.

Shortly after the impeachment, Randrianirina said the military had taken power and dissolved all institutions except the lower house of parliament or National Assembly.

Two sources close to the colonel told Reuters he would be sworn in as president in the next day or two, in the presence of officials from the High Constitutional Court, which invited him to serve as president on Tuesday.

Randrianirina told reporters on Tuesday that a committee led by the military would rule for up to two years alongside a transitional government before organising new elections.

Randrianirina, a commander in the elite CAPSAT army unit that played a key role in the 2009 coup that brought Rajoelina to power, broke ranks with him last week.

In a defiant address to the nation on Monday night, Rajoelina said that he had been forced to move to a safe place because of threats to his life. An opposition official, a military source and a foreign diplomat told Reuters he had fled the country on Sunday aboard a French military plane.