The Global Sumud Flotilla is using about 50 civilian boats to try and break Israel’s naval blockade of Gaza. Many lawyers and activists, including Swedish climate campaigner Greta Thunberg, are on board.

“We have sent one ship and another is on its way, ready for any eventuality,” Crosetto said in a speech to the lower house of parliament.

Italy sent a first frigate on Wednesday, hours after the GSF said it was targeted by drones that dropped stun grenades and itching powder, in international waters 30 nautical miles (56 km) off the Greek island of Gavdos.

The GSF blamed Israel for the attack.

The Israeli foreign ministry did not respond directly to the accusation, but repeated an invitation for the flotilla to drop humanitarian aid in an Israeli port, leaving it to Israeli authorities to take it to Gaza, or else face consequences.

Spain has also decided to send a military warship to protect the flotilla.

Crosetto warned the activists against insisting on trying to break the Israeli blockade, and urged them to accept an Italian proposal to hand over their aid supplies and allow them to be distributed in Gaza by the local Catholic Church.

“We cannot guarantee the safety of our fellow citizens if they enter the territorial waters of other countries,” Crosetto said.

The GSF said early on Thursday that its vessels were sailing at slow speed in Greek territorial waters, had been subjected to “moderate drone activity” during the night, and were heading towards international waters “later today”.