ALL EYES ON TURNOUT

Voter turnout will be critical to legitimising Ouattara's mandate if he wins as expected.

Roughly 80 percent of registered voters cast ballots in 2010. And while Ouattara said he was confident of a high level of participation, most voters and observers said the crowds were smaller on Sunday.

Leaders of a break-away faction of the Ivorian Popular Front (FPI), the party of ex-President Laurent Gbagbo, have called for a boycott of the election.

Gbagbo's refusal to recognise Ouattara's 2010 poll victory sparked the civil war, which killed around 3,000 people. Gbagbo is now in The Hague awaiting trial before the International Criminal Court charged with crimes against humanity.

The FPI hardliners have been joined by three candidates, including former Prime Minister Charles Konan Banny, who pulled out of the vote, saying the process was stacked in Ouattara's favour.

Polling stations in pro-Gbagbo villages in the former president's home region around the southwestern cocoa hub of Gagnoa were devoid of voters.

"My president is in prison," said Yves Titiro, a cocoa farmer in the village of Zebizekou, near Gagnoa. "In the north there will be an election, but it has nothing to do with us here."

The boycott is a challenge to Ouattara's efforts to mobilise voters. But it is also a test for his main opponent, FPI president Pascal Affi N'Guessan, who is leading his party's moderates in their first poll participation since 2010.

N'Guessan has criticised Ouattara for failing to foster post-war reconciliation and has chastised the FPI's own hardliners for endangering the party's future with their call for a boycott.

"I voted for the best one, and I can tell you it was Affi," said Elie Vakou, a voter in the mainly pro-Gbagbo Sicogie neighbourhood of Abidjan's Yopougon district. "If people vote for Affi, he can win and then free Gbagbo."