Israel’s government has vowed to prevent an aid boat carrying Greta Thunberg and other activists from reaching the Gaza Strip.

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.

Thunberg said she joined the Madleen crew to "challenge Israel's illegal siege and escalating war crimes" in Gaza and highlight the urgent need for humanitarian aid.