Brother of IS beheaded Tunisian shepherd killed
Khalifa Soltani was kidnapped on Friday in the Mount Mghilla area, and a security sweep recovered his body after a "terrorist group" announced his abduction, Belhassen Oueslati told AFP.
The Islamic State group claimed responsibility, according to the SITE Intelligence Group which monitors extremist organisations.
It quoted the IS Amaq agency as saying the man killed on Friday was a "spy... who worked for the benefit of the Tunisian intelligence on Mount Mghilla".
Oueslati did not provide further details about the victim, but media reports said he was the brother of Mabrouk Soltani, a 16-year-old shepherd who was decapitated on November 13, 2015.
The Tunisian branch of IS, Jund al-Khilafa (soldiers of the caliphate), claimed the killing, accusing the boy of betraying their movements to the army.
The circumstances of the latest death were not immediately known.
Nessma television said Khalifa Soltani's body was taken to a hospital in the central Kasserine region for an autopsy.
Prime Minister Youssef Chahed has called for a manhunt for the perpetrators and asked Defence Minister Farhat Horchani to head to the area, the channel said.
Meanwhile, the leftist Popular Front called for a demonstration in Tunis later on Saturday, "to denounce terrorism" and show solidarity with the Soltani family.
His killing comes less than a week after a top militant was shot and six others arrested in the Kasserine region's Mount Salloum area near the border with Algeria.
On Tuesday, the interior ministry said the six belonged to "sleeper cells" of Jund al-Khilafa.
It also clarified the militant killed on Sunday had belonged to the Okba Ibn Nafaa Battalion which is linked to al-Qaeda, and not to IS as it had previously said.
Since its 2011 revolution, Tunisia has experienced an increase in militant attacks that have cost the lives of dozens of members of the security forces and 59 foreign tourists.
The country has been under a state of emergency since November 2015, when a suicide bombing in Tunis claimed by IS killed 12 presidential guards.