Assailants killed 14 Tunisian soldiers in an attack on two posts near the border with Algeria, where the army has been waging a crackdown on jihadists, the government said Thursday.
"The toll is 14 dead soldiers and 20 wounded, and it is expected to rise," the defence ministry said, updating an earlier toll of four killed during the attack in the Mount Chaambi area.
"This is the heaviest recorded [death toll] to have been registered by the army since independence" in 1956, the ministry's press office told AFP.
The attacks came almost a year to the day since Tunisian soldiers were ambushed in the same region of Mount Chaambi, where the army has been hunting down a group with links to Al-Qaeda.
Eight soldiers were killed in the attack on July 29 last year which happened just days after the assassination of opposition politician Mohamed Brahmi in Tunis, causing a political crisis in the North African country.
Last month Al-Qaeda in the Islamic Mahgreb, or AQIM, for the first time claimed responsibility for recent attacks in Tunisia, including an assault in May on the home of the interior minister that left four security guards dead.
The May 27 attack on the home of Lotfi Ben Jeddou, in the western Kasserine region, killed four policemen.
Since late 2012, Tunisia's security forces have been battling jihadists hiding out in the Mount Chaambi and Kef regions and thought to be linked to AQIM.
Tunisia has been rocked by Islamist violence since the 2011 revolution that toppled a decades-old dictatorship and touched off the Arab Spring.
Authorities say they have gained the upper hand in the fight against jihadists active along the Algerian border, while acknowledging the campaign to root them all out will take time