Israel warned its military that it would “take any necessary measures” to prevent ships that have arrived in Gaza with pro-Palestinian activists and humanitarian aid.
Madleen yachts are 160 miles from the Gaza Strip and are trying to challenge Israel's ocean blockade around the territory.
Defense Minister Katz said 12 crew members, including climate protester Greta Thunberg, should look back and Israel will take action against any attempt to violate the lockdown.
The Free Fleet Alliance (FFC) said ships leaving Sicily on Friday were carrying humanitarian aid and “prepare for the possibility of an Israeli attack.”
Katz said the Israeli blockade, which has been around since 2007, is intended to “prevent the transfer of weapons to Hamas”, which is crucial to Israel's security as it tries to destroy Hamas, an armed group in Palestinian.
He warned in his post on X on Sunday: “I instructed the IDF [Israel Defense Forces] Take action to prevent “Madeleine” [sic] Hate Flotilla to reach the coast of Gaza and take any necessary measures. ”
Speaking directly to the crew, he added: “I am speaking to the anti-Semitic Greta and her Hamas propaganda spokesperson, and I say it clearly: You should look back – because you won’t be in Gaza.
“Israel will take any measures to break the blockade or assist terrorist organizations in the sea, air and land.”
The FFC believes that the maritime blockade is illegal and describes the minister's statement as an example of Israel's threat of illegal use of force against civilians and “try to prove violence against the smear.”
“We are not scared. The world is watching,” said FFC press officer Hay Sha Wiya.
“Madeline is a civilian ship, not armed and navigated in international waters, carrying humanitarian aid and human rights defenders from around the world…Israel has no right to prevent our efforts to reach Gaza.”
The team added that the ship had experienced temporary signal interference earlier, causing its location to appear near Jordan.
Madleen is carrying symbolic aid, including rice and infant formula, the group said.
People from Brazil, France, Germany, the Netherlands, Spain, Sweden and Turkey are all on board.
Israeli media said its navy is expected to block it before it arrives in Gaza.
“We will calmly control the ships, take them to Israel and expel them that night,” an Israeli official told the Jerusalem Post.
In 2010, Israeli commando killed 10 people when boarding the Turkish ship Mavi Marmara, which brought the aid fleet to Gaza.
Israel has recently begun allowing limited aid to enter Gaza after a three-month land blockade and has been prioritized through the Gaza Humanitarian Foundation (GHF), which is supported by Israel and the United States but is condemned by humanitarian groups.
Volker Türk, the head of human rights at the United Nations, said last week that Palestinians were shown as “the most severe option: die of hunger or danger, killed in trying to get the meager food available.”
Since Israel launched a military campaign in Gaza, it has been nearly 20 months since the Hamas-led cross-border attack on Israel, in which about 1,200 people have been killed and another 251 have been taken hostage.
At least 54,880 people have been killed in Gaza since then, according to the Hamas Ministry of Health in the region.
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