The anti-terrorism arm of Tunisia’s National Guard has launched a formal investigation into the murder of a man who disappeared two days ago in the central province of Sidi Bouzid after his head was found in a military no-go zone on Mount Mghilla.

Why it matters: The murder of construction worker Mohamed Lakhdar ben Salem Mahkloufi, 55, recalls the 2015 beheading of Mabrouk Soltani, a 16-year-old shepherd, on the same mountain. Soltani’s murder was claimed by Jund al-Khilafah, the Tunisian branch of the Islamic State, which advertised the beheading in a video and went on to murder the shepherd’s brother. In January a Tunisian court convicted 49 people in Soltani’s murder, including 45 in absentia. But nobody has yet claimed killing Mahkloufi.

Between a rock and a hard place: In June of last year, another shepherd was killed by jihadis in a closed military zone on Mount Chaambi in neighboring Kasserine province, near the Algerian border. The area is also home to the al-Qaeda-linked Okba Ibn Nafaa battalion, which executed two shepherds in 2015. Last year the group tortured another shepherd they accused of “espionage” on behalf of the security forces, beating him and cutting off his nose. The shepherd died of his wounds.

The al-Qaeda and Islamic State militants, whose numbers remain unknown but are estimated to be small, force villagers to provide them with food and other essentials. Should the villagers refuse, they face the prospect of ending up like the shepherds. When they cooperate with the militants, however, the villagers run the risk of winding up behind bars for “aiding terrorists.”