TUNIS, Tunisia (AP) — 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.

Tunisian authorities said the explosion came from inside the vessel, rejecting organizers’ claim that the vessel was hit by a drone off the country’s coast.

Officials in Tunisia said there was no evidence of an attack on the ship, which the Global Sumud Flotilla hoped to use to bring humanitarian goods to Gaza.