(AFP) - Madagascar's election race officially opened on Monday with all three recent presidents launching their campaigns ahead of the November 7 vote, which follows months of political tensions.

The Indian Ocean island suffers dire poverty and relies on foreign aid. It was rocked between April and June by protests in the main square of the capital Antananarivo over proposed electoral reforms.

The growing demonstrations forced President Hery Rajaonarimampianina to accept the formation of a "consensus" government tasked with organising the November election.

Among 36 candidates, the leading candidates are Rajaonarimampianina, who came to power in 2014, Marc Ravolamanana, the elected leader from 2002 to 2009, and Andry Rajoelina, who led the 2009 coup and held office until 2014.

"Given the crowds we have had today, we can already consider ourselves winners," Rajaonarimampianina, 59, told crowds on the outskirts of Antananarivo, promising the island would be self-sufficient in food in three years.

Ravolamanana, 68, held his rally at the central square in the city that was the focus of the protests against the president, telling his supporters that "we have just proven that Antananarivo belongs to us."

The square was occupied by demonstrators against Rajaonarimampianina's efforts to change electoral laws that opponents said were intended to favour his party.

The proposals were overturned by the courts.

But the protests morphed into a full-blown movement to oust Rajaonarimampianina. Clashes between activists and the security forces claimed two lives and left more than a dozen injured.

Ravolamanana's arch-rival Rajoelina, 44, began his campaign hundreds of miles (kilometres) away in the northern city of Diego Suarez, where he was welcomed by thousands of supporters wearing his party's orange colours.

Rajoelina, a former disc jockey and successful entrepreneur, hopes to use his youth and communication skills to rally support.

Madagascar was plunged into a protracted crisis when Rajoelina ousted president Marc Ravalomanana in the 2009 army-backed coup.

If, as is likely, no candidate receives more than 50 percent in the first round, a second round of voting will be held on December 19.

Accusations that the election will be rigged have already been aired by some of the candidates.

"Electoral fraud will take place using software in the electoral commission that will allow a candidate to have six times more votes than he actually had," said candidate Fanirisoa Ernaivo in front of a small crowd on Monday.

Madagascar, a former French colony with a population of 25 million, has been endured decades of political crises and grinding poverty.

© Agence France-Presse