Israel has intercepted a Gaza-bound aid ship carrying Greta Thunberg and other prominent activists, detaining those onboard, with the vessel being taken to Israel.

The activists had set out to protest Israel’s ongoing military campaign in the Gaza Strip, which is among the deadliest and most destructive since World War II, and its restrictions on the entry of aid.

The almost 20 months of war has torn Gaza apart, often displacing residents multiple times and killing more than 54,000 people, according to the Hamas-run Health Ministry. A U.S.-brokered ceasefire agreed in January collapsed in March as Israel enforced a blockade on all humanitarian aid into the strip.