Polling stations opened at 0700 GMT and will close at 1700 GMT, with 5.7 million people eligible to vote. Long queues were reported in Abidjan.

A close race is forecast between President Laurent Gbagbo and opposition candidate Alassane Ouattara.

The election is intended to reunite the country which split in two following a northern rebellion in 2002.

A night curfew has been imposed and will run until Wednesday, following a campaign beset by violence.

At least three people were shot dead in Abidjan on November 27 during protests against the curfew. Supporters of the opposition say it could open the door to electoral fraud.

Additional security forces have been deployed around the country and both Mr Gbagbo and Mr Ouattara have appealed for a peaceful vote.