Israeli forces intercepted a Gaza-bound aid boat on Monday, preventing the activists on board -- including Swedish campaigner Greta Thunberg -- from reaching the blockaded Palestinian territory.
The Madleen set sail from Italy on June 1 to raise awareness of food shortages in Gaza, which the United Nations has called the "hungriest place on Earth". After 21 months of war, the UN warns the entire population is at risk of famine.
At around 4:02 am (0102 GMT), Israeli forces "forcibly intercepted" the vessel in international waters as it was approaching Gaza, the Freedom Flotilla Coalition said.
"If you see this video, we have been intercepted and kidnapped in international waters," Thunberg said in a pre-recorded video shared by the coalition.
Footage from the group shows the activists w