Some parts of the military have joined these long-running protests/Screengrab
Madagascar's embattled President Andry Rajoelina is due to address the nation amid fears of a coup attempt.
His whereabouts are unclear, but he issued a statement on Sunday warning that an attempt to seize power by force was under way.
A senior army general has said the security forces are working together to maintain order in the island nation.
This follows two weeks of youth-led protests over high unemployment, the cost of living and corruption.
A powerful military unit has backed the protests.
The Gen Z Mada movement has been inspired by similar protests elsewhere, including in Nepal and Peru.
Hundreds of protesters have reportedly gathered in the capital to ramp up pressure on the president to resign.
An opposition leader has told the Reuters news agency that President Andry Rajoelina has left Madagascar, but that his final destination is not known.
Some parts of the military have joined these long-running protests. The same army unit - known as CAPSAT - that played a crucial role in regime change in 2009 now says it is command of all the armed forces.
"The president left the country, we called the staff of the presidency and they confirmed that he left the country" on Sunday, Siteny Randrianasoloniaiko is quoted as saying.
It follows reports by the French-language broadcaster RFI that Rajoelina had been airlifted from Madagascar on Sunday in a French military plane.
