Tunisian soldiers killed in attack near Algerian border
At least 14 Tunisian soldiers have been killed in a militant attack near the Algerian border with at least 20 others wounded, the defence ministry says.
They say gunmen, armed with rocket-propelled grenades and rifles, raided two checkpoints near Mount Chaambi.
It is reportedly the heaviest death toll registered by the army since independence in 1956.
The Tunisian army has been waging a crackdown on militants operating in the mountainous region over the past year.
Islamist militants, including fighters linked to al-Qaeda in the Islamic Mahgreb (AQIM), are believed to be hiding out in the border region.
Analysis: Naveena Kottoor, Tunis
Tunisians are in shock after what is being described as the deadliest attack on its armed forces since independence. The public is calling into question the strategy of the government, with renewed criticism being directed at Interior Minister Lotfi Ben Jeddou.
Following the attack, Prime Minister Mehdi Jomaa set up a "crisis cell" to come up with a coordinated government strategy. Details of exactly which militant group carried out the attack remain opaque - more information is expected later in the day.
Tunisia's security forces are under pressure to secure not only the western border with Algeria, but also the border to the east with Libya. It has one of the smallest armies in the region, with little experience in the kind of counter-terrorism operation it is now engaged in. The country has received support both in terms of training and equipment from Europe and the United States.
2014 was meant to be the year of rebranding the country as the cradle of stability and progress in North Africa. The Tunisian government wants to attract more tourists, especially to less travelled regions in the north-west and south of the country, but attacks like this are likely to trigger travel warnings abroad and keep visitors away.
The soldiers were attacked "by terrorist groups" on Wednesday evening as they were breaking their fast as part of the Muslim holy month of Ramadan, Tunisia's Tap state news agency reports.
A group called the Okba Ben Nafaa Brigade has reportedly said it carried out the attack in a post on its Facebook page.
The office of the Tunisian presidency has declared three days of mourning starting on Thursday, Tunisian TV reports.
Eight soldiers were killed in an attack in the Mount Chaambi district in July 2013, days before the assassination of secular politician Mohamed Brahmi, which plunged the country into political turmoil.
Islamist militants have been increasingly active around the Algerian-Tunisian border since the 2011 Arab Spring uprising that toppled long-term leader Zine al-Abidine Ben Ali.