Exit polls show former Tunisian Prime Minister Beji Caid Essebsi has the lead in the country’s run-off presidential election as vote counting is still underway.

The polling firm Sigma Conseil says 88-year-old Essebsi is set to win over 55 percent of the votes while his rival, incumbent President Moncef Marzouki, will garner less than 45 percent.

Essebsi’s campaign team also claimed victory by a clear margin based on initial “indications.” However, the rival camp contested the claims and described the announcement as baseless.

Essebsi, who represents the secular-leaning Nidaa Tounes party, served as a prime minister in the regime of former dictator Zine El Abidine Ben Ali and is more popular in Tunisia’s wealthy coastal regions.

This is while Marzouki has strong support in the conservative south. He is a human rights activist who was forced into exile by the Ben Ali regime.

Tunisians went to polls Sunday in what has been described as the last step in their transition to democracy after they ousted Ben Ali in the 2011 uprising. The votes marked the first time Tunisians elected their president directly.

Essebsi won the first round in November with 39 percent of the votes. The official result of the run-off vote is expected to be announced between December 22 and 24.

Tunisia has beefed up security as threats by extremist groups have been intensified over the past days.

On Sunday, clashes erupted between police and gunmen when a voting station was attacked in central Kairouan region hours before the votes opened. Police killed one armed man and arrested three others in the incident.