Israeli officials have said the blockade is necessary to prevent weapons smuggling into the enclave.
Conditions in Gaza have worsened considerably since the deadly Hamas-led attack on Israel in October 2023, which ignited the current war, now in its 20th month.
Israel recently banned the entry of any humanitarian aid for 80 days, bringing the territory to the brink of famine, according to international aid organisations.
The Madleen is probably carrying only a symbolic amount of humanitarian aid. The coalition said in a statement that it was bringing urgently needed goods, including baby formula, flour, rice, nappies, medical supplies and children’s prosthetics.
But Israel’s Defence Minister, Israel Katz, said he had instructed the country’s military to prevent the vessel from reaching Gaza.
In a blunt statement, he said, “To Greta the anti-Semite and her friends, propagandists for Hamas – I say clearly: You would do well to turn back, because you won’t get to Gaza".
“Israel will act against any attempt to breach the blockade or aid terrorist organisations by sea, air or land.”
Thunberg has been an outspoken opponent of Israel’s naval blockade of Gaza and its actions in the enclave.
“We are doing this because, no matter what odds we are against, we have to keep trying,” Thunberg said last week.
“Because the moment we stop trying is when we lose our humanity. And no matter how dangerous this mission is, it’s not even near as dangerous as the silence of the entire world in the face of the livestreamed genocide.”
Israel’s military has blocked past attempts by pro-Palestinian activists to bring aid to Gaza by sea, including by force.
In 2010, nine passengers aboard the Mavi Marmara, part of a flotilla carrying aid from Turkey to Gaza, were killed in an Israeli commando raid, stirring international outrage and damaging Turkish-Israeli relations. A 10th passenger died from his wounds years later.
Israel said at the time that its soldiers, some of whom had rappelled on to the ship from helicopters, fell into an ambush and were attacked with clubs, metal rods, and knives.
The Freedom Flotilla Coalition has described the interception of the Mavi Marmara as “an unlawful and deadly attack” and said the Madleen’s mission is “a continuation of that legacy – a refusal to surrender to silence, fear or complicity” in the face of the siege of Gaza.
Another recent attempt by the coalition to challenge the blockade was thwarted.
A ship called Conscience left Tunisia in late April carrying human rights activists and aid and was scheduled to stop in Malta to pick up more people, including Thunberg.
However, the ship was rocked by explosions off the coast of Malta, setting it on fire.
The passengers and crew were not harmed, but the mission was abandoned.
Israel has since lifted its total ban on the entry of humanitarian aid and in recent weeks has backed a new system aimed at getting help to Palestinians without Hamas being able to divert or benefit from it.
The effort got off to a troubled start as Israeli forces fired at hungry and desperate Palestinians on their way to collect boxes of food at a distribution site in southern Gaza, killing and wounding scores of them.
The distribution sites are being operated by American security contractors under the auspices of a new organisation, the Gaza Humanitarian Foundation.
That effort has been boycotted by the United Nations and other prominent aid groups, which accuse Israel of using aid as a weapon.
The foundation said it had distributed more than 1.1 million meals today across three distribution sites.
In addition, the group said it had delivered 11 truckloads of food directly to community leaders through local merchants as part of a pilot project aimed at easing crowding at the existing distribution points.
At the weekend, the foundation said it was “impossible to proceed” with the distribution of aid that day, accusing Hamas of threatening its operations.
A group spokesperson today shared a written warning he said local staff members had received threatening them with “serious consequences” if they continued working for the programme.
Written by: Isabel Kershner
This article originally appeared in The New York Times.
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