The Palestinian Hamas group in Gaza blamed Israel on Saturday for the killing in Tunisia this week of a Tunisian national it described as one of its drone experts, and threatened retaliation.
Hamas's armed wing, the Qassam Brigades, said Mohammed Zawari, who was gunned down near the city of Sfax on Thursday, had been a member of the group for 10 years and had been supervising its drone programme.
Hamas, which rules the Gaza Strip, did not offer any evidence to support its accusation. A spokesman for Israeli Prime Minister Benjamin Netanyahu did not respond to a Reuters request for comment.
"Qassam Brigades mourns the martyr of Palestine, martyr of the Arab and Muslim nation, the Qassam leader, engineer and pilot Mohammad Zawari, who was assassinated by Zionist treacherous hands on Thursday in Sfax," a statement posted on the group's website said.
"The enemy must know the blood of the leader Zawari will not go in vain," the statement said.
The Tunisian interior ministry said Zawari was killed in his car by multiple gunshots in front of his house in El Ain, near Sfax, on Thursday. Four rental cars were used in the killing and two handguns and silencers were seized, the ministry said.
Television footage aired on local media showed a black Volkswagen with its windows apparently shot out.
A judicial spokesman from Sfax, Mourad Tourki, told Tunisian radio Shems FM eight Tunisian nationals had been arrested in connection with the killing.
One of the suspects is a Tunisian journalist based in Hungary, arrested along with a cameraman. Two other suspects, one of them a Belgian of Moroccan origin, are still at large, Tourki said.
Authorities have not commented on who is suspected of being behind the killing.
Local media said Zawari had returned to Tunisia in 2011 after spending two decades abroad, including in Syria. They gave his age as 49 and said he was a technical director in a private engineering firm and a model aircraft expert.
Israel has in the past voiced concern that armed groups in Gaza and Lebanon would deploy drones carrying explosives inside its borders in a future war. Hamas and other Islamist militias have fired thousands of rockets at militarily superior Israel in previous offensives by the latter on Gaza, but have made scant use of drones.
In September the Israeli army said it had intercepted a drone off the coast of Gaza.
It was the first such incident reported since the 2014 Israeli offensive on Gaza , when a U.S.-supplied Israeli Patriot missile destroyed an unmanned Hamas aircraft over the southern Israeli port city of Ashdod. Israel is itself a world leader in drone technologies and has used the vehicles extensively in combat.
In 2010 a Mossad hit-team assassinated Hamas operative Mahmoud al-Mahbouh in Dubai.
*This story was edited by Ahram Online.