Tunisian Prime Minister Habib Essid lost a confidence vote in parliament Saturday, in a move that risks plunging the country into fresh political uncertainty.

Tunisia's Islamist Ennahda party will separate it religious activities from political ones, its chief said in statements published Thursday ahead of a weekend congress to formalize the change.

Rached Ghannouchi, an intellectual who once advocated a strict application of Islamic sharia law, told French daily Le Monde there was no room left in post-Arab Spring Tunisia for "political Islam".

Tunisia's military has killed a jihadist described as "one of the most dangerous terrorist leaders" in the country during a security operation, the defense ministry said Thursday.

Seifeddine Jameli, as known as Abou al-Qaaqaa, belonged to the Tunisian branch of the Islamic State (IS) group, Jund al-Khilafa (the soldiers of the caliphate), the ministry said in a statement.

Tunisia's President Beji Caid Essebsi said in Doha on Thursday that his country's battle to fight "terrorism" has cost it around $4 billion diverted away from the country's economy.

"The war against terrorism has cost Tunisia a lot, about $4 billion," Essebsi told reporters in Qatar, at the end of an official three-day visit to the Gulf country.

The Tunisian government said Thursday that 37 suspects, including several jihadists linked to the Islamic State group, had been arrested in the security operations carried out the previous day.

Two "dangerous and wanted terrorists" were killed during the raid Wednesday in Mnihla near the capital, while 16 suspected jihadists were arrested, the interior ministry said Thursday.

Four policemen and three suspected jihadists were killed during security operations Wednesday near the capital and in southern Tunisia, in the latest violence to hit the country, officials said.

The European Union pledged Monday to intensify efforts to aid Tunisia as it tackles economic troubles and a jihadist threat in its transition to democracy five years after its revolution.

"The European Union sees it is necessary and obvious to mobilize all our efforts to support the Tunisian government and people in order for the democratic transition and country to succeed," EU foreign policy chief Federica Mogherini said after a meeting in Luxembourg with Tunisian Foreign Minister Khemaies Jhinaoui.

Tunisia reopened its border crossings with Libya on Tuesday after a two-week closure in response to a deadly jihadist attack on a town near the frontier, the interior ministry said.

The move came as Tunisia hosted talks with other countries neighboring Libya on the threat posed by the growing Islamic State (IS) group presence in the lawless North African nation.

Tunisia's security forces have killed a "terrorist" outside the southern border town of Ben Guerdane where jihadists mounted a deadly assault earlier this month, authorities said Monday.

"A terrorist element holed up in a house was killed in the Sayah area" near the Libyan border, the interior and defense ministries said in a joint statement.

Tunisia arrested 17 suspects Tuesday in a manhunt for jihadists near the Libyan border after a deadly raid it described as an unprecedented assault by the Islamic State group.