(AFP) - Former Madagascan president Andry Rajoelina has beaten his rival and predecessor Marc Ravalomanana in an election beset by allegations of fraud, the electoral commission said Thursday.

Rajoelina has returned to power after he won 55.66 percent against 44.34 percent for Ravalomanana in the run-off vote held last week, it said.

The results, announced under high security, were quickly appealed by Ravalomana.

The defeated candidate filed papers with the Constitutional Court just hours after the electoral commission announced the election's complete results.

The court has nine days to formally name the new president after it has reviewed the petition.

Ravalomana's campaign director Anisoa Tseheno Rabenja accused the electoral commission of a "premeditated act" in helping Rajoelina commit "massive fraud".

- 'Massive fraud' -

Rajoelina meanwhile called for unity and a "democratic" transfer of power as he thanked those who voted for him and those who did not.

"I already came first in the first round, and the people of Madagascar have confirmed my victory in this second round," he said Rajoelina.

"What matters is that the people of Madagascar were able to express themselves freely," he added.

"My message is simple, the people of Madagascar no longer need a crisis, they need a wise, unifying leader".

Rajoelina, 44, sat in the front row among the 200 guests in the room where the electoral commission announced the results.

A seat next to him, apparently reserved for Ravalomanana, was empty, according to an AFP journalist.

"It's unfortunate that the other candidate is not here," the president of the electoral commission, Hery Rakotomanana, said.

The electoral commission chief said "efforts were made to respond" to concerns raised by both candidates, which included a review of the counting software.

The two-round election was plagued by mutual accusations of vote-rigging in a country with a long history of instability.

Heavily-armed police patrolled the area around the electoral commission offices for the announcement.

No victory celebrations were witnessed on the streets of the capital.

Rajoelina and Ravalomanana are former presidents and long-time rivals who have fought a fiercely personal duel for power.

They each spent lavishly on campaigning, with promises and handouts distributed liberally to voters, who are among the poorest in Africa.

- 'People expressed themselves freely' -

European Union election observers have said they had not seen evidence of wrongdoing in the vote in which about five million ballots were cast.

Ravalomanana, a 69-year-old former milkman who built a business empire, had on Sunday urged supporters to protest what he called "injustice and a violation of their right to vote".

Elected president in 2002, he was forced to resign seven years later following protests fuelled by Rajoelina, who had been elected mayor of the capital Antananarivo.

Rajoelina was then installed by the army and ruled until 2014.

He is a former events planner and successful entrepreneur with slick communication skills.

The two adversaries came a close first and second in the preliminary election in November, with Rajoelina garnering 39 percent compared with 35 percent for Ravalomanana.

The two candidates were both banned from running in the 2013 election as part of an agreement to end recurring crises that have rocked Madagascar since independence from France in 1960.

Outgoing president Hery Rajaonarimampianina was eliminated in the first round after winning only nine percent.

Just 48.09 percent of the eligible 10 million voters cast their votes in the run-off, slightly lower than in the 55 percent in the first round.

Madagascar is well known for its vanilla and precious redwood, yet is one of the world's poorest nations, according to World Bank data, with 76 percent of people living in extreme poverty.

The island, which is also famed for its unique wildlife, is dependent on foreign aid and burdened by a long history of coups and unrest.

© Agence France-Presse