Israel has intercepted a Gaza-bound aid ship carrying Greta Thunberg and other prominent activists, detaining those onboard, with the vessel being taken to Israel.

The Freedom Flotilla Coalition (FFC) earlier said the Israeli military had boarded the Madleen, which was attempting to deliver aid to Gaza.

“The passengers are expected to return to their home countries,” Israel’s Foreign Ministry said in a post on X.

Climate activist Thunberg, Game of Thrones actor Liam Cunningham and Rima Hassan – a French member of the European Parliament – are among those on the Madleen.

The FFC group posted a photo on Telegram early Monday local time, showing members of the crew sitting inside the boat wearing lifejackets and with their hands in the air.

No Israel Defence Force soldiers can be seen in the image.

In an earlier post, the FFC said the ship had come “under assault in international waters.”

“Quadcopters are surrounding the ship, spraying it with a white paint-like substance. Communications are jammed, and disturbing sounds are being played over the radio,” FFC said on its Telegram channel.

Israel has repeatedly vowed to stop the aid boat from reaching Gaza, and described the ship as a “selfie yacht” carrying “celebrities”.

“I have instructed the IDF to ensure that the ‘Madleen’ flotilla does not reach Gaza,” Israeli defence minister Israel Katz said on Sunday.

The aid boat first reported signs of Israeli military action in the early hours on Monday morning.

“Just a short while ago, two Israeli drones were above the FFC Madleen and dropped or sprayed some sort of white chemical on the Madleen. Now the Madleen seems to be surrounded by Israeli naval commandos,” Huwaida Arraf, Freedom Flotilla organiser and steering committee member and US human rights lawyer, told CNN.

In a video livestreamed from the boat and posted by the FFC, activist Yasmin Acar showed a white substance on the deck, saying it had been dropped on the vessel.

Acar was later heard saying it was affecting her eyes.

Before the live stream ended, Acar could be heard saying the Israeli military was communicating with the board.

Israel’s foreign ministry said the group “attempted to stage a media provocation whose sole purpose was to gain publicity”.

“There are ways to deliver aid to the Gaza Strip — they do not involve Instagram selfies,” it added.

The crew, which has publicised the location of the ship with an online tracker, began preparing for the possibility of interception by the Israeli military.

As of Monday morning, the UK-flagged civilian vessel was north of Egypt in the Mediterranean Sea, slowly approaching the coast of Gaza.

“We know that it’s a very risky mission and we know that previous experiences with flotillas like this have resulted in attacks, violence and even cases of death,” Thunberg told CNN on Saturday.

After an 11-week blockade that prevented any humanitarian aid from entering Gaza, Israel has begun allowing a trickle of aid in once again.

But it is only a fraction of the aid that entered the enclave before the war, with humanitarian organisations warning of a worsening humanitarian crisis and the growing risk of widespread famine.

Israel’s foreign ministry earlier posted video on X showing a Navy staffer issuing what appears to be a radio message to the vessel.

“The maritime zone off the coast of Gaza is closed to maritime traffic,” the unidentified Navy staff member is heard saying. She is later heard saying aid needs to be delivered through “established channels.”

In a statement, the ministry said “unauthorised attempts to breach the blockade are dangerous, unlawful, and undermine ongoing humanitarian efforts.”

“We call on all actors to act responsibly and to channel humanitarian aid through legitimate, coordinated mechanisms, not through provocation,” the ministry added in a statement on Monday local time.