Madagascar's President Andry Rajoelina has pushed back his long-awaited national address, deepening uncertainty over his whereabouts after days of protests calling for his resignation.

Rajoelina has faced the most serious test to his presidency since taking office, with weeks of street protests, which were later joined by a mutinous army unit.

The 51-year-old leader has not appeared in public since last Wednesday and is believed to have fled the country aboard a French military plane, according to Radio France Internationale. French authorities did not respond immediately to AFP's request for confirmation.

Rajoelina was due speak to the nation at 7pm (1600 GMT), but it was delayed by an hour and half after "a group of armed forces threatened to take control of the state-owned media," the presidency said on Facebook.

Protests escalate

The presidency did not name who had attempted to block the broadcast.

Newly appointed Chief of the Army Staff, General Demosthene Pikulas, "went to the site to mediate, organise and take action against the situation," it said.

The protests initially focused on chronic power and water cuts in Madagascar but developed into a broader anti-government movement that called for Rajoelina to resign.

The United Nations has said that at least 22 people were killed in the first days of the protests, but the government says the death toll is less.