JERUSALEM — Activists say Israeli troops have boarded a yacht trying to bring humanitarian aid to the Gaza Strip, in defiance of an Israeli naval blockade.

"Connection has been lost" on the Madleen, the Freedom Flotilla Coalition (FFC) campaign group said on the Telegram app.

It posted a photo showing people in life jackets sitting with their hands up.

Appearing to confirm that the ship had been boarded, Israel's foreign ministry said the yacht was "safely making its way to the shores of Israel" and its passengers were "expected to return to their home countries".

Climate activist Greta Thunberg is among those aboard the vessel, which was reported to be off the Egyptian coast.

Israel says its blockade is necessary to prevent weapons from reaching Hamas militants in Gaza.

After reporting that the yacht had been boarded, the FFC posted short, pre-recorded videos of some of the activists, including Thunberg.

In the footage, activists say "if you see this video, we have been intercepted and kidnapped" by the Israeli military or forces supporting Israel.

The FFC earlier said the vessel, which left Italy's island of Sicily on Friday, was carrying humanitarian aid and had been "prepared for the possibility of an Israeli attack".

Israeli Defense Minister Israel Katz had warned that the yacht should turn back and that Israel would act against any attempt to breach the blockade.

He wrote in a post on X on Sunday: "I have instructed the IDF [Israel Defense Forces] to act to prevent the 'Madeleine' [sic] hate flotilla from reaching the shores of Gaza - and to take whatever measures are necessary to that end."

Katz says the purpose of Israel's blockade, which has been in place since 2007, is to "prevent the transfer of weapons to Hamas" and is essential to Israel's security as it seeks to destroy Hamas.

The FFC has argued that the sea blockade is illegal, characterizing Katz's statement as an example of Israel threatening the unlawful use of force against civilians and "attempting to justify that violence with smears".

"We will not be intimidated. The world is watching," FFC press officer Hay Sha Wiya said.

"The Madleen is a civilian vessel, unarmed and sailing in international waters, carrying humanitarian aid and human rights defenders from across the globe... Israel has no right to obstruct our effort to reach Gaza."

The Madleen is carrying a symbolic quantity of aid, including rice and baby formula, the group said.

Citizens of Brazil, France, Germany, the Netherlands, Spain, Sweden and Turkey are on board.

In 2010, Israeli commandos killed 10 people when they boarded Turkish ship Mavi Marmara that was leading an aid flotilla towards Gaza.

Israel recently began to allow limited aid into Gaza after a three-month land blockade, prioritizing distribution through the Gaza Humanitarian Foundation, which is backed by Israel and the US but widely condemned by humanitarian groups.

The UN's human rights chief, Volker Türk, said last week Palestinians were being presented with the "grimmest of choices: die from starvation or risk being killed while trying to access the meager food that is being made available".

But in a post on X early on Monday, the Israeli foreign ministry said: "While Greta and others attempted to stage a media provocation whose sole purpose was to gain publicity - and which included less than a single truckload of aid - more than 1,200 aid trucks have entered Gaza from Israel within the past two weeks, and in addition, the Gaza Humanitarian Foundation has distributed close to 11 million meals directly to civilians in Gaza.

"There are ways to deliver aid to the Gaza Strip - they do not involve Instagram selfies."

It is almost 20 months since Israel launched a military campaign in Gaza in response to the unprecedented Hamas-led cross-border attack on Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.

At least 54,880 people have been killed in Gaza since, according to the territory's Hamas-run health ministry. — BBC