Hamas on Saturday accused Israel of killing a Tunisian scientist who was murdered in the country on Thursday and vowed to avenge his death.
Mohamed Zaouari, a 49-year-old aviation engineer, was murdered at the wheel of his car outside his house in the Tunisian city of Sfax.
Al-Qassam Martyrs Brigade, Hamas’s armed wing which controls Gaza, told AFP on Saturday that drone expert Zaouari was killed by "Zionist treachery", referring to Israel.
It said Zaouari had worked for the "resistance" for 10 years, and announced a day of mourning.
"Zaouari's assassination in Tunisia is aggression against the resistance, and Al-Qassam Brigades and the enemy should know that the blood of the leaders will not be wasted and lost in vain," it said in a separate statement quoted by AFP.
Reports first surfaced Friday of Zaouari’s death, with a Tunisian journalist claiming that the Mossad had been following the engineer for quite some time, and is responsible for his death.
Hamas spokesman Mushir Al-Masri said on Friday he did not rule out the possibility that Israel was behind the engineer’s death, saying, "The only body that would benefit from the assassination is the Zionist entity."
Tunisia's Islamist Ennahdha movement has called for an investigation into the killing, which it said posed a threat to the country's stability.
The local interior ministry said Saturday a Tunisian woman had been arrested the previous evening at the capital's Carthage airport, suspected of involvement in the murder.
She was a journalist arriving from Hungary who had previously interviewed the victim, deputy prosecutor general Mourad Turki told the private radio station Shems FM.
A total of "eight suspects have been arrested and they are all Tunisians", he added.
Four vehicles have been seized, along with two guns equipped with silencers, the interior ministry said.
Private radio station Mosaique FM reported that Zaouari's body was riddled with 20 bullets.
He was buried on Saturday in Sfax, media in Tunisia reported.
Zaouari was reportedly known for innovations in the field of aviation. His death comes as Hamas continues to rebuild its infiltration tunnel network into Israel, after the IDF destroyed the network during Operation Protective Edge in 2014.
In addition, the group has invested considerable resources in the development and procurement of weapons, including long-range missiles that cover most of the territory of the State of Israel.
As part of these efforts, Hamas conducts ongoing missile tests meant to advance its domestic rocket arsenal ahead of its next terror war against Israel.