(AFP) - The opposition in Madagascar vowed Friday to keep holding protests despite a top court order that presidential elections be postponed by one week amid high political tensions, after disputes over the regularity of the vote.

For more than a week, opposition parties have held demonstrations against what they call an "institutional coup" to keep outgoing president Andry Rajoelina in power.

Eleven out of 13 opposition candidates have led almost daily, unauthorised marches in the capital, Antananarivo, which have been met with a heavy police presence.

Voters in the Indian Ocean island nation were initially due to head to the polls on November 9.

But the country's top court on Thursday ordered that presidential elections be postponed by one week -- an order ratified on Friday by a government decree.

"We must not give up, we must go all the way", Marc Ravalomanana, former president and candidate in the next elections, told AFP during a demonstration in the capital Antananarivo.

The election -- in which the outgoing president Andry Rajoelina is also a candidate -- has been in preparation for several weeks in a climate that continues to deteriorate.

It was the latest twist in a political crisis that has gripped the country since Rajoelina, 49, resigned last month in line with the constitution in order to run for re-election.

The ruling follows the injury of candidate Andry Raobelina at one of the protest rallies that have routinely been dispersed by police.

"This postponement means nothing," said opposition candidate, Roland Ratsiraka, saying it was not up to the constitutional court "to decide when the ballot should take place".

"The Constitution is clear that the government decides on the basis of a proposal from the electoral commission," he said.

"Tomorrow there will be ten times as many of us", he warned.

Andry Rajoelina, 49, first took power in 2009 on the back of a coup that ousted Ravalomanana.

After not running in the 2013 election due to international pressure, he was voted back into power in 2018.

Last month, ten opposition candidates denounced an "institutional coup" orchestrated by the government.

The Constitutional Court dismissed appeals to have Rajoelina's candidacy declared void over his dual French nationality, sparking opposition anger.

Press reports earlier this year revealed that he had been naturalised as a French citizen in 2014.

© Agence France-Presse