The international flotilla trying to deliver aid to Gaza said early that drone activity is increasing over the flotilla as it nears the destination.
"We have now entered the high-risk zone, the area where previous flotillas have been attacked and/or intercepted," the Global Sumud Flotilla said in post on Telegram.
The flotilla, consisting of more than 40 civilian boats with over 500 people including parliamentarians, lawyers and Swedish climate campaigner Greta Thunberg, aims to break Israel's blockade of the Palestinian enclave.
In a later post on Telegram, the Global Sumud Flotilla said that several of its boats were approached by unidentified vessels, some navigating without lights.
It said that the vessels have departed, and participants implemented security protocols in anticipation of a possible interception.
Italy and Spain deployed navy vessels last week to assist the flotilla, after it was hit by drones armed with stun grenades and irritants in international waters off Greece, but without any intention to engage militarily.
Israel did not respond to flotilla accusations that it was behind last week's attacks, but it has vowed to use any means to prevent the boats from reaching Gaza, arguing that its blockade is legal as part of its war against Hamas militants.
Israel began its Gaza offensive after the 7 October, 2023, Hamas-led attack on Israel in which some 1,200 people were killed and 251 taken as hostages, according to Israeli tallies.
The offensive has since killed over 66,000 Palestinians, Hamas-run health authorities in Gaza say.
