Departing from Catania in southern Italy, their vessel, the Madleen, is part of the Freedom Flotilla Coalition.
The group's goal is to bring essential aid to Gaza and raise international awareness about what they describe as “an unbearable humanitarian disaster.”
The journey is expected to take seven days to reach their destination — if they are not stopped.
This isn’t Thunberg’s first attempt to join such a mission. She was initially slated to participate in a similar effort in May, but the journey was disrupted when the vessel was allegedly attacked by drones in international waters, a strike the group blamed on Israel.
Israel maintains the blockade is necessary to pressure Hamas into releasing hostages taken during the 7 October attack.
With over 52,000 Palestinians killed and Gaza in ruins, critics accuse Israel of collective punishment. Israel insists it only targets militants.