More than 10 suspects have already been detained in relation to the March 13 assault, when assailants armed with grenades and assault rifles stormed three hotels in Grand-Bassam, a beachside resort popular with foreigners 40 kilometres from Abidjan.
The attack, the first of its kind in the Ivory Coast, was claimed by Al-Qaeda in the Islamic Maghreb, which has also carried out assaults on tourist hotspots in Mali and Burkina Faso.
Around 20 people were wounded in the incident.
Ould Sidy Mohamed Sina "was the contact of the alleged planner" of the attack, Ciss added.
Despite the slew of arrests, the Malian man believed to be the main brains behind the attack, identified as Kounta Dallah, is still at large.