Tunisian President Moncef Marzouki
Tunisian President Moncef MarzoukiReuters

Tunisians voted on Sunday to pick their first directly elected president, with the two major parties expecting a run-off, Reuters reports.

Official results were yet to be announced, but shortly after polls closed, the parties of two front-runners said initial tallies showed they had passed to a second round run-off next month.

Beji Caid Essebsi's secularist Nidaa Tounes party said he was ahead in Sunday's election by at least 10 percentage points. Essebsi and rival Moncef Marzouki, the incumbent president, were expected to be front-runners, but analysts had said neither was likely to avoid a run-off in December.

"Essebsi is ahead according to initial results, with a big difference to the next candidate," Essebsi's campaign manager Mohsen Marzouk told reporters, according to Reuters. "There is a strong possibility of a second round."

The campaign manager for Marzouki said their candidate would get through to the second round with Essebsi, but gave no polling figures.

Political parties have observers at polling stations who act as witnesses to oversee preliminary counts, which allows them to tally results unofficially for their party.

More than three years since overthrowing dictator Zine el-Abidine Ben Al, Tunisia adopted a new constitution, and rival secularists and Islamist parties have largely avoided the turmoil that has plagued other Arab states swept by popular revolts.

Sunday's vote follows the general election in October when the Nidaa Tounes party won the most seats in the parliament, beating the Islamist party Ennahda that had won the first free poll in 2011.

Ennahda, which gave up power after being accused by the opposition of seeking to entrench itself in power, disregarding the interests of a large secular urban population and being lenient toward radical Islamists, had chosen not to nominate a candidate to run in the presidential election.