The office of Madagascar's President Andry Rajoelina has said an attempt to seize power illegally and unconstitutionally is under way in the country.

Hours later, an army unit known as CAPSAT claimed that it had taken over the leadership of the military command, and was now in control of all the armed forces - land, air, and naval.

This is the same unit that played a crucial role in the 2009 Malagasy political crisis, which helped Rajoelina rise to power.

Madagascar was first hit by protests on 25 September against water and power cuts, but they have escalated to reflect wider dissatisfaction with Rajoelina's government over high unemployment, corruption, and the cost-of-living crisis.

Rajoelina's statement said "there is an attempt to seize power at this time in the territory of the Republic, in complete violation of the Constitution and democratic principles," in a translation.

He condemned "in the strongest possible terms" what he called an attempt to destabilise the country. He also called on all of the nation's key forces to unite in defending the constitutional order and national sovereignty.

CAPSAT said it had appointed a new chief of staff, Gen Demosthene Pikulas, according to a statement issued on its Facebook page.

On Sunday morning, there were reports of a shoot-out at the CAPSAT camp after officials from the gendarmerie visited it for discussions. No further details have emerged of the incident.

On Saturday, some soldiers had left their barracks on the outskirts of the capital, Antananarivo, to join protesters in front of the city's town hall.

CAPSAT had condemned the use of force by security forces in handling recent protests in Antananarivo.

On Saturday, a statement from the presidency had assured the nation that Rajoelina and the new prime minister - an army general he appointed last week - were in control of the situation.