The Freedom Flotilla Coalition (FFC) has said the Israeli military has boarded its Gaza-bound aid ship carrying Greta Thunberg and that communication with the boat has been lost.

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.

Israeli forces stopped a Gaza-bound aid boat and detained Greta Thunberg and other activists who were on board early Monday, enforcing a longstanding blockade of the Palestinian territory that has been tightened during the war with Hamas.