One of the Gaza-bound vessels carrying aid and pro-Palestinian activists including Greta Thunberg was struck by a drone, the flotilla organisers have claimed.
Global Sumud Flotilla (GSF) posted footage on Instagram that appeared to show the Portuguese-flagged vessel being hit by an object, and said all six passengers and crew were safe after the incident outside the Tunisian port of Sidi Bou Said.
Tunisian authorities quoted by Reuters said reports a drone was involved had no basis in truth, adding an initial inspection indicated the explosion originated inside the vessel.
The humanitarian aid flotilla set sail from Barcelona last week and arrived in Tunisia on Sunday.
The GSF said their Family boat was struck in Tunisian waters, and fire had damaged the main deck.
In a series of videos published to their Instagram, spokespeople for the GSF said an incendiary device caused a fire onboard the vessel, which the crew was able to extinguish.
A spokesperson for the Tunisian national guard also told the AFP news agency no drone had been detected and the investigation was continuing.
David Heathcote, Head of Intelligence at McKenzie Intelligence Services, told the BBC the nature of the impact angle in footage implies that the object has been dropped, rather than launched or fired. He added that if a drone was used, it could have been maneuvered over the ship before the package was released onto it.
United Nations Human Rights Council special rapporteur Francesca Albanese, who was among the GSF group, stated that if the attack is verified, it would be considered an assault and aggression against Tunisia, and Tunisian sovereignty.
In March, Israeli forces boarded a boat carrying humanitarian aid to Gaza and detained the 12 activists onboard, including Thunberg. Israeli authorities have described these attempts to sail aid to Gaza as mere publicity stunts.
Earlier this year, a UN-backed body confirmed the presence of famine in Gaza, a claim Israel has disputed.
