In an earlier video, Acar said the activists had “sighted 15 to 16 drones”, adding their radios had been jammed as loud music could be heard.
One video posted by the flotilla’s official Instagram page showed an explosion it said it recorded from the Spectre boat at “01:43 GMT +3”.
In another video posted by the same page, Brazilian activist Thiago Avila said four boats had been “targeted with drones throwing devices” just before another explosion was heard in the background.
The Global Sumud Flotilla set sail from Barcelona this month with the aim of breaking Israel’s blockade of Gaza and delivering aid to the territory.
It currently numbers 51 vessels, most of which are situated off the Greek island of Crete.
It had already been targeted in two suspected drone attacks in Tunisia, where its boats had been anchored before resuming its voyage towards Gaza.
Among its high-profile participants is environmental activist Greta Thunberg.
Israel said Monday it would not allow the boats to reach Gaza.
Israel blocked two earlier attempts by activists to reach Gaza by sea in June and July.
Israel has come under international pressure over its war in Gaza, which has sparked a dire humanitarian crisis in the Palestinian territory.
Last month, a body backed by the United Nations officially declared famine in part of Gaza.
And on September 16, UN investigators accused Israel of committing “genocide” in the besieged territory, nearly two years after the war erupted after Hamas’ October 7, 2023, attack on Israel.
– Agence France-Presse