Organizers of a flotilla carrying aid for Gaza have reported explosions near their boats and seeing multiple drones around the fleet, which is made up of more than 500 people, including prominent environmental activist Greta Thunberg.

Global Sumud Flotilla (GSF) which was sailing near Greece as of early Wednesday, according its online tracker, also saw its communications “jammed,” its organizers said in a statement.

“We are witnessing these psychological operations first-hand, right now, but we will not be intimidated,” they added. “Sumud” in Arabic means “steadfastness” or “steadfast perseverance.”

In an online video shared by GSF overnight, a bright light can be seen piercing the darkness, before a loud blast rings out. Organizers said that the video was filmed from one of its boats, Spectre, and that it captured one of the explosions heard by crew members.

In a separate video posted by Yasemin Acar on the vessel Alma, music from the pop group ABBA, whose members, like Thunberg hail from Sweden, can be heard ringing out. “They’re jamming our radio,” Acar says in the post, adding, “We do not know where this is coming from, the sound, but other vessels are experiencing the same thing.”

TOPSHOT-PALESTINIAN-ISRAEL-CONFLICTA Palestinian child evacuates southward, along a road in the Nuseirat refugee camp area, in the central Gaza Strip on Tuesday.Eyad Baba / AFP via Getty Images

Thunberg told Reuters in a video interview Tuesday that drones were flying above them every night “but for Palestinians, especially in Gaza, those drones are dropping bombs constantly.”

“This mission is about Gaza, it isn’t about us. And no risks that we could take could even come close to the risks the Palestinians are facing every day,” she said.

Italian Defense Minister Guido Crosetto condemned the incident Wednesday, saying he had directed a navy ship to offer assistance, Reuters reported.

GSF did not immediately respond to a request for further comment from NBC News. Israel’s military and a spokesperson for Prime Minister Benjamin Netanyahu’s office also did not immediately respond to NBC News’ requests for comment Wednesday.

But the Israeli Foreign Ministry condemned the flotilla Monday. Without providing any evidence, Oren Marmorstein, a spokesperson for the ministry, said in a statement on X that the flotilla was “organized by Hamas” and “intended to serve Hamas.”

He added that Israel would not allow the flotilla to “enter an active combat zone and will not allow the breach of a lawful naval blockade.”

Marmorstein also called for the flotilla to dock at Israel’s Ashkelon Marina and unload aid there for it to be transferred to Gaza.

But GSF has argued that Israel is violating international law in its deadly offensive in Gaza, rendering the country’s blockade illegal.

The flotilla, which is carrying more than 500 people from more than 40 countries, set sail from Barcelona late last month in a bid to “break the illegal siege of Gaza.”

Earlier this month, GSF said that two of its boats had been attacked by drones while stationed in Tunisia.

The Tunisian Interior Ministry said at the time that reports of a drone hitting a boat at its Sidi Bou Said port had “no basis in truth,” and that a fire broke out on the vessel itself, according to Reuters.

The latest accusations come as Israeli forces continue their devastating assault on Gaza City that has seen scores killed in recent days and forced the displacement of hundreds of thousands of people. Deaths from starvation have also continued to rise in the enclave this month, according to Palestinian health officials.

Israel launched its offensive in Gaza following the Hamas-led attacks in 2023, when 1,200 people were killed and around 250 were taken hostage, according to Israeli officials, marking a major escalation in a decadeslong conflict. Since then, Palestinian health officials say, more than 65,000 people have been killed in Gaza, including thousands of children, while much of the enclave has been reduced to rubble.

This week, Tom Barrack, the U.S. special envoy to Syria and ambassador to Turkey, accused Israel of “attacking everybody,” in an interview with The National, the state-owned English-language daily newspaper based in the United Arab Emirates.

He named Syria and Lebanon among those attacked, as well as Tunisia, in an apparent reference to the alleged attack on the aid flotilla.

“Personally, I hate what’s happened in Gaza on all sides,” Barrack told the newspaper “For the Palestinians, for the Israelis, for the Jordanians, for the Lebanese, for the Syrians, for the Turks. You know … it’s a mess.”

“Israel is a valued ally,” Barrack said. “We subsidize them” by $4 billion to $5 billion a year. “It has a special place in America’s heart, and we’re living with the confusion of what’s happening in this transition.”

“So it’s complicated,” he added.