Israel's defence minister has threatened to "take whatever measures necessary" to stop an aid boat carrying Greta Thunberg from reaching Gaza.
The climate campaigner, 22, is one of a dozen activists aboard the Madleen, which set sail from Sicily last Sunday on a mission aiming to break Israel's sea blockade.
The activists have said they plan to reach Gaza's territorial waters as early as Sunday to deliver humanitarian aid.
But in a post on X, Israel's defence minister Israel Katz said he has instructed the IDF to prevent the vessel reaching shore and to "take whatever measures necessary".
Addressing Thunberg and the other activists, he said: "You should turn back - because you will not reach Gaza."
He wrote: "I have instructed the IDF to act so that the "Madeleine" hate flotilla does not reach the shores of Gaza - and to take any means necessary to that end.
"To the anti-Semitic Greta and her fellow Hamas propaganda spokespeople, I say clearly: You should turn back - because you will not reach Gaza.
"Israel will act against any attempt to break the blockade or assist terrorist organizations - at sea, in the air and on land."
Rima Hassan, a French member of the European Parliament, who is of Palestinian descent, is also on the boat, which is operated by the Freedom Flotilla Coalition.
She has been barred from entering Israel because of her opposition to Israel's policies towards Palestinians.
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Israel started allowing some basic aid into Gaza last month after a three-month total blockade aimed at pressuring Hamas and preventing the group from importing arms.
But humanitarian workers have warned of famine unless there is an end to the blockade and the 20-month war, which was ignited by the Hamas-led attack on southern Israel on 7 Oct 2023.
An attempt last month by Freedom Flotilla to reach Gaza by sea failed after another of the group's vessels was attacked by two drones while sailing in international waters off Malta.
The group blamed Israel for the attack, which damaged the front section of the ship.
(c) Sky News 2025: Israel's defence minister vows to stop aid boat carrying Greta Thunberg from reaching Gaza
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