Incumbent President Azali Assoumani is facing five challengers for his bid for a fourth term.

For months, some of the candidates have threatened to boycott the election over the detention of political prisoners and concerns about the poll's credibility.

Mr Assoumani, 65, is a former military officer who first came to power after a coup in 1999.

Both President Assoumani and the electoral body CENI have assured the country of a transparent election.

More than 300,000 people are registered to vote in the tiny African archipelago, the population of which is estimated at 836,000 by the World Bank.