Anti-Islamist candidate Beji Caid Essebsi has claimed victory in Tunisia's first free presidential election but bitter rival and incumbent Moncef Marzouki has refused to concede defeat.
Tunisians voted on Sunday for the leadership runoff vote, with many calling the ballot a landmark for democracy in the country where the Arab Spring was born.
Official results are not due until Monday evening but shortly after polls closed Essebsi's campaign manager Mohsen Marzouk said early indicators signalled a victory for Essebsi, leader of the Nidaa Tounes party.
Essebsi, 88, appeared before 2,000 supporters who gathered outside his campaign headquarters shouting "Long live Tunisia!" and thanked the voters.
"Tunisia needs all its children. We must work hand in hand," he said as supporters cheered.
Marzouki's campaign chief Adnene Mancer said the result was too close to call, and accused the Essebsi camp of election "violations".
It is the first time Tunisians have freely elected their president since independence from France in 1956.
Authorities had urged a big turnout to consolidate democracy following a chaotic four-year transition. Election organisers said turnout was at 59.04 per cent.
Just hours before polling began at 0700 GMT, troops guarding ballot papers in the central region of Kairouan came under attack and shot dead one assailant and captured three, the defence ministry said.
Prime Minister Mehdi Jomaa condemned what he called a "desperate attempt" to disrupt the election, and later told AFP that what had happened was of no "impact", adding that the security situation was under control.
The authorities had deployed tens of thousands of soldiers and police to provide security for polling day.
