The Israeli military on Wednesday intercepted the Global Sumud Flotilla, a fleet of nearly 50 boats carrying humanitarian aid sailing toward the besieged Gaza, said activists on board.

At least 19 of the fleet’s boats were intercepted by the Israeli Navy about 70 nautical miles from Gaza, the Associated Press quoted the activists as saying.

Among the nearly 500 persons on board the 50 boats were climate activist Greta Thunberg, Nelson Mandela’s grandson Mandla Mandela, former Barcelona mayor Ada Colau and several European lawmakers.

“Israel has committed yet another breach of international law to block those who confront the genocide in Gaza,” stated the Freedom Flotilla Coalition, an international campaign against the blockade of the Palestinian territory.

It added: “We will not stop. We will sail until Gaza is free. Brave hearts to the front. Free Palestine.”

Israel’s foreign ministry said that “Greta and her friends were safe and healthy”, adding that they were being transferred to Israel.

In a separate post, the ministry said that the passengers were now on board yachts “making their way safely and peacefully to Israel, where their deportation procedures to Europe will begin”.

Earlier, Israel had posted a video purportedly showing a naval officer stopping the flotilla from approaching Gaza, saying it was an active combat zone.

“The sole purpose of the Hamas-Sumud flotilla is provocation,” the ministry said in a social media post.

It claimed the flotilla had been warned that it was entering an “active combat zone” and violating a lawful naval blockade, and that activists were offered an alternative “safe channel” for aid delivery.

Greg Stoker, one of the activists on board the flotilla, claimed they were sprayed with water cannons.

The organisers added that since the flotilla was civilian and humanitarian and not armed, its passage was lawful under international law, the Associated Press reported.

The flotilla began its journey from ports in Spain and Italy in August, sailing via Greece and Tunisia, Al Jazeera reported.

After a two-and-a-half-month blockade aimed at pressuring Palestinian militant group Hamas, Israel started allowing basic aid into Gaza in May. However, humanitarian workers have continually warned of famine unless the blockade is lifted and Israel ends its military offensive.

Two earlier attempts by the Freedom Flotilla to reach Gaza were stopped by Israeli forces in May and June.

Israel has maintained a formal naval blockade on Gaza since 2009, citing the need to prevent weapons smuggling. Authorities have also alleged links between some flotilla organisers and Hamas – a claim the activists have denied.

Israel’s current military offensive against Gaza began in October 2023 after Hamas killed 1,200 persons during its incursion and took hostages. Israel has been carrying out unprecedented air and ground strikes on Gaza since then, killing more than 62,600 persons, including nearly 17,500 children.