TEL AVIV – Hamas said the Mossad was behind Thursday’s killing of Mohammed Al-Zoari, a Tunisian aviation engineer who developed unmanned drones for the terror group, and vowed revenge.

Hamas said the death of Zoari, a “pioneer” who “acted against Israel, in the defense of Palestine,” was an attack against it.

“[Hamas’ military arm Izz ad-Din] Qassam Brigades mourns the martyr of Palestine, martyr of the Arab and Muslim nation, the Qassam leader, engineer and pilot Mohammad Zoari, who was assassinated by Zionist treacherous hands on Thursday in Sfax,” a statement by the Gaza-based terror group said. “The enemy must know the blood of the leader Zoari will not go in vain.”

According to Hamas, 59-year-old Zoari had been a member of its military wing for the past 10 years, in charge of its drone program.

Senior Hamas official Mushir al-Masri told a Tunisian radio station that “the Zionist enemy” would benefit from the assassination of Zoari, and reminded listeners that the Mossad has a history of killing experts engaged in the development of UAVs.

Tunisian newspapers also said Israel was behind the killing of Zoari, who was shot dead by unidentified assailants in his car outside his home in the Tunisian city of Sfax.

A senior Tunisian journalist said the Mossad had been tracking the engineer for quite some time, Israel’s Channel 10 reported.

Tunisian authorities arrested eight suspects and seized four cars that had two pistols with silencers in them.

According to senior court official in Sfax, Murad a-Turki, the investigation yielded a “connection to other elements who are now outside the country,” but there was no evidence linking Zoari’s death to Israel.

Zoari developed innovations in unmanned aircraft. According to Lebanese daily Al Akhbar, the engineer had also helped Lebanon-based terror group Hezbollah develop UAVs. The Tunisian also had links to the local Muslim Brotherhood – the Tunisian government’s rivals – which forced him to leave for Syria in 1991. He returned in 2011 after the overthrow of former Tunisian president Zine El Abidine Ben Ali kicked off the Arab Spring.

Israel has so far made no comment on the killing.