A plane carrying the exiled former leader of Madagascar was forced to return to Johannesburg after authorities in his homeland closed the country's air space.

Marc Ravalomanana, who has spent the past three years in South Africa, said he wanted to return home in order to implement a plan to restore democracy in the Indian Ocean island nation. But security forces in Madagascar had warned he would be arrested.

He had been sentenced in absentia to life in prison for the dozens of opposition protesters killed by his presidential guard in 2009, ahead of the coup that toppled him.

Last September, Ravalomanana agreed to a plan that allowed military-backed President Andry Rajoelina, the coup leader, to remain in power until elections are held.

Under the proposal, Ravalomanana would have been allowed to return to Madagascar, after an attempt early last year to fly home was also thwarted.