An international activist group seeking to deliver aid to Gaza on a flotilla says one of its boats was hit by what it believes was a drone while docked in Tunisia. Tunisian authorities denied a drone was involved, and said they are investigating a fire in a life jacket aboard the boat.

The Global Sumud Flotilla said in a statement overnight that a vessel known as the “Family Boat” and travelling under a Portuguese flag “was struck by a drone”, but that no one aboard was hurt.

Footage posted on the group's social media showed a flash of light landing on one of the boats and setting off what appears to be a fire.

The group, whose flotilla was scheduled to leave Tunisia tomorrow, is expected to give a news conference in Tunis later today about what happened. It said the incident would not derail its mission to deliver aid to Gaza.

The flotilla is part of a broad movement seeking to deliver aid to Gaza by boat.

The Tunisian Interior Ministry said in a statement that reports about a drone attack were unfounded, and that specialised security units are investigating the results of a fire in a life jacket.

The Israeli military and Israeli government did not immediately respond to requests for comment.