The attempt to block the flotilla carrying the famed climate activist comes 15 years after a similar aid effort ended in deadly violence.

Israel is supporting armed groups of Palestinians in Gaza in what it says is a move to counter Hamas. But officials from the U.N. and aid organizations say the military is allowing them to loot food and other supplies from their trucks.

Palestinian witnesses said Israeli forces had fired on them at a roundabout in the nearby city of Rafah as they went to get food from a site run by the Gaza Humanitarian Foundation (GHF). The Israeli military said it fired warning shots at people it said were suspects who had advanced toward its forces and ignored warnings to turn away.