JERUSALEM (AP) — Israel's army chief says his forces underestimated the threat they faced when they boarded a Gaza-bound flotilla in May.

Lt. Gen. Gabi Ashkenazi says soldiers should have done more to ensure "sterile conditions" on the ship — indicating more force was needed to subdue pro-Palestinian activists before soldiers boarded the vessel.

He says the commandos used only two stun grenades to clear the area before rappelling from helicopters onto the ship, which was trying to break Israel's blockade of Gaza.

Ashkenazi told an official inquiry Wednesday the activists beat Israelis with clubs and metal rods, even fired shots. Soldiers responded with gunfire, killing nine Turkish activists.

The incident drew international criticism and forced Israel to loosen the blockade.