Greta Thunberg's Gaza flotilla has now entered a so-called "high-risk zone" after ignoring calls to stop its attempt to breach an Israeli naval blockade.
The Global Sumud Flotilla (GSF) said in a statement: "We have now entered the high-risk zone, the area where previous flotillas have been attacked and/or intercepted."
And just before 4am in the UK, it claimed that several of its boats were approached by unidentified vessels, some navigating without lights.
On Tuesday, Italian Prime Minister Giorgia Meloni pleaded with the flotilla to stop their voyage immediately, suggesting the activists risk wrecking the "fragile balance" of the peace proposal set out by US President Donald Trump.
In a statement, she said: "Many would be happy to disrupt [the peace plan].
Greta Thunberg's Gaza flotilla has now entered the 'high-risk zone' after ignoring calls to stop
|GETTY
"I fear that the flotilla's attempt to breach the Israeli naval blockade could provide a pretext for this. Also for this reason, I believe the flotilla should stop now."
But GSF organisers clapped back at the Italian leader, saying: "We say again: the flotilla sails onwards.
"The humanitarian demand to break the blockade cannot be walked back to port."
One Al-Jazeera correspondent on board the flotilla claimed that reconnaissance drones had been spotted flying over the sailing area in the Mediterranean.
Italian Prime Minister Giorgia Meloni pleaded with the flotilla to stop their voyage immediately
|REUTERS
While Turkish pro-Palestine activist Muhammed Salih said a ship from the Israeli navy had been detected fewer than 50 miles from the small fleet.
In a video posted to social media, Mr Salih said: "We were already expecting an Israeli interception or attack this evening or tomorrow night.
"Most likely, it will happen tonight. We are on high alert.
"Everyone has put on their life jackets and is waiting ready on deck."
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The flotilla consists of more than 40 civilian vessels, with over 500 activists believed to be on board.
Those on the Gaza cruise include various pro-Palestinian politicians and lawyers from around the world, in addition to Ms Thunberg.
On Tuesday, Israeli national broadcaster KAN said the country's navy was preparing to seize the ships as they approach the Gaza Strip in violation of the maritime blockade.
Authorities are planning to move the GSF sailors on to a warship and bring them back to the Port of Ashdod, the Israeli outlet reported.
The flotilla consists of more than 40 civilian vessels with over 500 activists believed to be on board
| REUTERSThe flotilla is believed to be carrying humanitarian aid, food and medical supplies, and set sail at the end of August.
After the fleet was struck by mysterious "drones carrying stun grenades" last week, the Italian and Spanish navies deployed boats to accompany the activists.
Israel has not said whether its military were behind the drone strike, but vowed it would use any measure necessary to stop the boats reaching Gaza as part of its war on Hamas.
Pope Leo has also weighed in, telling reporters at the Vatican: "From all sides, people are saying: 'Let's hope that there will not be violence, that people are respected.' That's very important."
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