Israeli forces have intercepted a flotilla of aid boats attempting to break the maritime blockade of the Gaza Strip, detaining crews in international waters near the southern Greek island of Crete.

The incident occurred overnight on Wednesday into Thursday, according to activists.

The Global Sumud Flotilla, which set sail from Barcelona earlier this month, aimed to deliver humanitarian aid to Gaza.

Organisers said that more than 70 boats and 1,000 participants from across the globe were involved, with additional vessels joining as it traversed the Mediterranean.

This latest attempt to break the blockade follows a similar effort by the activist group less than a year ago, which was also thwarted by Israeli authorities.

In a press release, the group said: “Israel’s actions … mark a dangerous and unprecedented escalation, the abduction of civilians in the middle of the Mediterranean, over 600 miles from Gaza, in full view of the world.”

Israel’s foreign ministry said on X that about 175 activists from over 20 boats were being taken to Israel.

The blockade on Gaza, enforced by Israel and Egypt to varying degrees since Hamas took control in 2007, is justified by Israel as a measure to prevent arms imports. However, critics argue it constitutes collective punishment of the Palestinian population in Gaza.

Turkey’s foreign ministry condemned the seizure of the flotilla as “an act of piracy”.

“By targeting the Global Sumud Flotilla, whose mission is to draw attention to the humanitarian catastrophe faced by the innocent people of Gaza, Israel has also violated humanitarian principles and international law,” the ministry said in a statement.

Turkish foreign ministry spokesperson Oncu Keceli wrote on X that Turkish foreign minister Hakan Fidan had discussed the raid over the phone with his Spanish counterpart Jose Manuel Albares Bueno.

Activists in Greece said they planned a protest rally on Thursday afternoon outside the Greek foreign ministry in Athens, saying Israel’s interception of the boats occurred within the maritime zone that falls under Greece’s responsibility for search and rescue operations and that the country’s coast guard had not reacted.

A fragile six month-old ceasefire in Gaza has halted the most intense fighting between Israeli forces and Hamas-led militants in the Palestinian enclave. But despite the ceasefire, Israeli attacks have killed more than 790 people, according to Gaza’s health ministry.

The ministry, part of the Hamas-led government, maintains detailed casualty records that are seen as generally reliable by UN agencies and independent experts. It does not give a breakdown of civilians and militants.

Overall, the health ministry says 72,300 Palestinians have been killed since the war in Gaza began with the 7 October 2023 Hamas-led attack on Israel.

Around two million Gaza residents are still living in ruins with shortages of food and medicine, and only limited aid entering through a single, Israeli-controlled border post.

Flotilla organisers have said they hope their latest attempt to reach Gaza will help highlight the living conditions endured by Palestinians in the territory, particularly as global attention has shifted its focus to the US and Israel’s war against Iran.

The flotilla’s effort to breach the blockade in 2025 saw dozens of boats sailing near Gaza, with one crossing the 12 nautical mile (22km) line marking the divide from international waters to territorial waters. But all were ultimately intercepted and seized or turned away.

Those sailing included Swedish climate activist Greta Thunberg.

Israel arrested, detained and later deported the participants, who claimed Israeli authorities abused them while in detention. Israeli authorities denied the accusations.