Israeli forces stopped a Gaza-bound aid boat carrying Greta Thunberg and other activists early Monday and diverted it to Israel, enforcing a longstanding blockade of the Palestinian territory that has been tightened during the war with Hamas.

"The 'selfie yacht' of the 'celebrities' is safely making its way to the shores of Israel," the Foreign Ministry said in a social media post. "The passengers are expected to return to their home countries."

It said the humanitarian aid aboard the ship would be transferred to Gaza through established channels. It later circulated footage of what appeared to be Israeli military personnel handing out sandwiches and water to the activists, who were wearing orange life vests.

The Freedom Flotilla Coalition, which had organized the voyage to deliver humanitarian aid to the Gaza Strip and protest Israel's blockade and wartime conduct, said the activists had been "kidnapped by Israeli forces" and released pre-recorded messages from them.

Thunberg, a climate campaigner, was among 12 activists aboard the Madleen, which set sail from Sicily a week ago. Along the way, it had stopped on Thursday to rescue four migrants who had jumped overboard to avoid being detained by the Libyan coast guard.

Rima Hassan, a French member of the European Parliament who is of Palestinian descent, was also among the volunteers on board. She has been barred from entering Israel because of her opposition to Israeli policies toward the Palestinians.

After a 2.5-month total blockade aimed at pressuring Hamas, Israel started allowing some basic aid into Gaza last month, but humanitarian workers have warned of famine unless the blockade is lifted and Israel ends its military offensive.

An attempt last month by Freedom Flotilla to reach Gaza by sea failed after another of the group's vessels was attacked by two drones while sailing in international waters off Malta. The group blamed Israel for the attack, which damaged the front section of the ship.

Israel and Egypt have imposed varying degrees of blockade on Gaza since Hamas seized power from rival Palestinian forces in 2007. Critics of the blockade say it amounts to collective punishment of Gaza's roughly 2 million Palestinians.

Israel sealed Gaza off from all aid in the early days of the war ignited by the Hamas-led attack on southern Israel on Oct. 7, 2023, but later relented under U.S. pressure. In early March, shortly before Israel ended a ceasefire with Hamas, the country again blocked all imports, including food, fuel and medicine.

Hamas-led militants killed around 1,200 people, mostly civilians, in the Oct. 7 attack and abducted 251 hostages, more than half of whom have since been released in ceasefire agreements or other deals. Hamas is still holding 55 hostages, more than half of them believed to be dead.

Israel's military campaign has killed more than 54,000 Palestinians, according to the Gaza Health Ministry, which has said women and children make up most of the dead. It doesn't say whether those killed are civilians or combatants.

The war has destroyed vast areas of Gaza and displaced around 90% of the territory's population, leaving people there almost completely dependent on international aid.