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.

The group is carrying supplies for Gazan Palestinians and protesting what they say is “Israel’s “illegal, decades-long blockade, and ongoing genocide” in the enclave.