Israeli Prime Minister Benjamin Netanyahu directly approved military operations on two vessels that were part of a Gaza-bound flotilla carrying aid and pro-Palestinian supporters, including Swedish climate activist Greta Thunberg, CBS News reported on Friday.
Two American intelligence officials briefed on the matter told CBS News that Israeli forces on Sept. 8 and 9 launched drones from a submarine and dropped incendiary devices onto the boats that were moored outside the Tunisian port of Sidi Bou Said, causing a fire.
The officials spoke under the condition of anonymity because they were not authorized to speak publicly on national security matters.
Under international humanitarian law and the law of armed conflict, the use of incendiary weapons against a civilian population or civilian objects is prohibited in all circumstances.
The Global Sumud Flotilla organized the international maritime initiative that aims to break through Israel's naval blockade of Gaza and provide aid to the war-torn territory.
On Sept. 8, an incendiary device was dropped onto the Family, a Portuguese-flagged vessel. The Global Sumud Flotilla told CBS News that on the night prior to the attack, Portuguese lawmaker Mariana Mortagua was on board.
The activists believe the perpetrators deliberately waited until "elected officials or high-profile figures were absent," the group stated in a press release to CBS News on Friday.
On Sept. 9, the Alma, a British-flagged vessel, was attacked similarly to the Family. In both cases, the group said last month that the fire damaged the boats, but the crew was able to extinguish the flames quickly. No one was killed or injured.
"Confirmation of Israeli involvement would not surprise us; it would simply lay bare a pattern of arrogance and impunity so grotesque that it cannot escape eventual reckoning," the Global Sumud Flotilla said in its statement Friday.
The statement added: "Whether the purpose of these attacks was to kill us, scare us away, or disable our boats, they recklessly endangered civilians and humanitarian volunteers. The world must take note: attempts to silence, intimidate, or obstruct our commitment to the Palestinian cause and people will not succeed."
"We call for urgent, independent investigations into these attacks and full accountability for those responsible," the statement noted.
Tunisian authorities disputed in September that drones dropping incendiary devices caused the fire, instead claiming that an initial inspection indicated the explosion originated inside the boat, according to BBC News.
Pro-Israeli accounts on social media claimed the fires were started after the activists did not use a flare gun properly.
Footage released by the Global Sumud Flotilla and obtained by CBS News appears to show a ball of flames falling onto the boat, sparking the fire on board, instead of the fire originating from inside the vessel.
The stationary cameras affixed to the vessels do not capture where the flames originated from prior to landing on the boat, nor do they depict a flare gun being fired.
In separate incidents in late September, the activist group said they were attacked by 15 low-altitude drones while sailing south of Greece. The Global Sumud Flotilla said at least 13 explosions were heard on and around several flotilla boats and objects were dropped on at least 10 boats, causing damage. While no casualties were reported, the activist group said that their communications systems were also disrupted.
This week, Israeli naval forces intercepted most of the vessels bound for Gaza, detaining dozens of activists along with Thunberg and several European lawmakers, a move that drew swift international criticism.
Israel has also detained American citizens traveling on the flotilla. A State Department official told CBS News that the department was monitoring the situation and is committed to assisting U.S. citizens.
The official also called the flotilla a "deliberate and unnecessary provocation," particularly as the Trump administration continues to seek a negotiated solution to end the war in Gaza.
Two Americans sailing with the Global Sumud Flotilla include Marine Corps veteran Jessica Clotfelter and Greg Stoker, organizer of the veterans' delegation to the group. On Wednesday, they spoke via Zoom to CBS News Chicago roughly an hour before the Israeli navy intercepted the flotilla.
"We are a civilian aid mission, trying to break the siege into Gaza, and we are carrying humanitarian aid in accordance with international humanitarian and maritime law," Stoker said.
Clotfelter told CBS News Chicago that the images that have been coming out of Gaza for the last two years have been "heartbreaking" and "gut-wrenching."
She added: "I mean, I've cried probably every single day on this boat as the violence since we've taken off on Aug. 31 has escalated."