Israel’s military used drones to drop a “white irritant substance” on Greta Thunberg’s Gaza-bound aid boat before boarding and detaining the activists.

Pictures from the Madleen yacht showed the deck covered in white liquid, which had been sprayed from a drone at around 2am BST, according to the group behind her mission. It was not immediately clear what the liquid was.

The Freedom Flotilla Coalition (FFC), which organised the voyage, said “Quadcopters are surrounding the ship, spraying it with a white irritant substance.”

Ms Thunberg and 11 other passengers from the Madleen are being taken to the Israeli port of Ashdod, where the Israel Defense Forces has been ordered to show them a video of the Oct 7 attacks by Hamas before they are deported.

The activists had set out to protest against Israel’s ongoing military campaign in the Gaza Strip, and its restrictions on the entry of humanitarian aid.