Israel Defense Minister Israel Katz on Sunday ordered the military to block an aid boat on its way to Gaza carrying a dozen activists, including Swedish climate campaigner Greta Thunberg.

Katz instructed the Israel Defense Forces (IDF) “to act so that the ‘Madeleine’ hate flotilla does not reach the shores of Gaza — and to take any means necessary to that end,” the minister said in a statement on X.

“Israel will act against any attempt to break the blockade or assist terrorist organizations — at sea, in the air and on land,” Katz said.

Katz was referring to the Madleen, a ship operated by the Freedom Flotilla Coalition, which left Italy earlier this month. It has described its mission as a “peaceful act of civil resistance,” aiming to deliver supplies for the people of Gaza, including baby formula, diapers, women’s sanitary products, water desalination kits, medical supplies, crutches and children’s prosthetics.

The organizers said Sunday afternoon they were “about 160 nautical miles from Gaza.”

“Israel’s defense minister has once again threatened unlawful force against civilians, attempting to justify violence with baseless smears,” the Freedom Flotilla Coalition said on Instagram. “We will not be intimidated.”

Earlier Sunday, at least five people were killed by gunfire on their way to two aid distribution points in Gaza run by an Israeli and U.S.-backed group, the Associated Press reported.