Tunisians voted on Sunday in the country’s first presidential election since the 2011 uprising that triggered protests across the region.
More than 25 candidates are in the race, but incumbent Moncef Marzouki and Beji Caid Essebsi, head of the leading secular party Nida Tounes are widely seen as the favorites.
The poll forms part of a political transition after the revolution that ousted Zine al-Abidine Ben Ali, the BBC wrote.
A parliamentary vote was held in October.
Tunisia - seen as the birthplace of the “Arab Spring” - is considered to have had the most successful outcome, with relatively low levels of violence.
Sunday’s election will deliver the country’s first directly elected leader since the removal of Ben Ali. Most polling stations opened at 08:00 (07:00 GMT) and were due to close 10 hours later.
If no candidate wins more than 50% of the vote, a run-off round will be held on 31 December.
Essebsi, from the Nidaa Tounes (Tunisia’s Call) party, is the favorite to win after his party came first in the parliamentary election.
But critics say Essebsi, an 87-year-old who served in the governments of post-independence leader Habib Bourguiba as well as Ben Ali, represents the past.
Among the other candidates are Marzouki, parliamentary Speaker Mustapha Ben Jaafar, Republican Party leader Ahmed Nejib Chebbi, female magistrate Kalthoum Kannou and businessman Slim Riahi.
The Ennahda party, which led Tunisia’s last government but was beaten by Nidaa Tounes in October’s parliamentary election, did not field a candidate.
A statement from Ennahda leader Rachid Ghannouchi spoke of wanting “to avoid deepening polarization or dividing the country”.
Tunisia is still facing the specter of civil unrest and terrorism, with Interior Minister Lotfi Ben Jeddou warning of “serious security threats” near the Algerian border where al-Qaeda militants are said to be hiding.
