TUNIS: Tunisia said Thursday that an attack on a Tunis museum last week was launched by a cell of 23 militants, including an Algerian and Moroccans, with overlapping allegiances to a number of hard-line Islamist groups.

Tunisian Interior Minister Najem Gharsalli said 80 percent of the group had already been arrested over the killing of 20 tourists, including Japanese, French and Italians, in an attack claimed by ISIS.

“This cell is linked to Okba Ibn Nafaa and Al-Qaeda in the Islamic Maghreb, most of them came originally from Ansar al-Shariah,” Gharsalli said. 

Ansar al-Shariah is listed as a terrorist group by Washington. Okba is mainly based in the Chaambi Mountains bordering Algeria. That group has been tied to Al-Qaeda in the Islamic Maghreb’s original Algerian leadership but it has also issued ambiguous statements about links to ISIS.

Lines are blurring between Islamist militants in North Africa as members of local Al-Qaeda affiliates are drawn to ISIS’ high-profile attacks following its success in seizing swaths of territory in Iraq and Syria last year.

The Bardo attack is testing Tunisia just as the North African country is being hailed as an example for democratic transition, four years after its “Arab Spring” uprising ousted autocrat Zine al-Abidine Ben Ali.

Western leaders, including France’s Francois Hollande and Italy’s Prime Minister Matteo Renzi, are expected for a large march in solidarity Sunday, local officials said.

Since its 2011 revolution, Tunisia mostly avoided the turmoil facing other “Arab Spring” countries. Secular and Islamist politicians have compromised to make their transition work, approve a new constitution and hold free elections.

But security forces have been waging a low-level war against Islamist militants. Until the Bardo attack though, most militant assaults were focused on security forces in remote areas.