Three Tunisian soldiers were killed and seven others wounded on Monday when Islamist militants opened fire on them.
Army spokesman, Belhassen Ouslati said the three soldiers were killed in a landmine blast and clashes were continuing after the ambush in the Mount Sammama area.
Jihadists use the remote, mountainous region along the Algerian border as a base and the military has been hunting them down in the rugged terrain with patrols and air strikes on suspected training camps.
A local Al Qaeda affiliate, Okba Ibn Nafaa, has been based in the Mount Chaambi range.
Some of its leadership is Algerian while some foreign militants fled there after the French intervention in Mali.
Since the 2011 uprising, Tunisia’s democracy has been held up as a model for a region wracked by violence and instability but Islamist militants are one of the key challenges for the new Prime Minister Youssef Chahed.
Militants occasionally carry out attacks on army patrols and checkpoints in the remote areas around Mount Chaambi, and occasionally raid local homes for food and supplies.