Tunisian authorities have denied claims that one of the Gaza-bound vessels carrying aid and pro-Palestinian activists including Greta Thunberg was attacked by a drone.

The organisers of the flotilla, Global Sumud Flotilla (GSF), said that the Portuguese-flagged vessel had been struck by a drone while anchored outside the port of Sidi Bou Said in Tunisia. All six passengers and crew were safe, they added.

A spokesperson for Tunisia's national guard told the Agence France-Presse news agency that "no drone" had been detected and the investigation was ongoing.

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.