RAFAH, Gaza Strip — Forty-six days after the July 8 start of the war on Gaza, Israel succeeded in assassinating three leaders of the Izz ad-Din al-Qassam Brigades, Hamas' military wing, prompting Hamas to execute 18 people it accused of spying for Israel. The Aug. 21 attack appears to have caught the organization off guard and has raised speculation of a possible lapse in security precautions that enabled Israel to successfully carry out the attack.

A statement issued by the brigades mourned the three men: Mohammed Abu Shamala, 41, a member of the general military council; Raed al-Attar, 40, commander of the Rafah brigade and a member of the general military council; and Mohammed Barhoum, 45, a top-ranked brigades member.

On Aug. 22, Hamas publicly executed the alleged spies working for Israel and issued an explanatory statement, “The revolutionary court’s decision to execute the death sentence of several spies.” The Majd website, which is close to Hamas, said that the collaborators' confessions included details of their actions, among them “following and monitoring leaderships, finding targets to hit the resistance — such as rocket launching pads and tunnels — and monitoring the movements of leaders, which resulted in their martyrdom.”

The confessions also included “delivering information on resistance members who have been targeted, providing detailed descriptions of the houses of a number of resistance members that have been destroyed during the war, determining civil and military sites and targets through GPS devices, collecting phone numbers of resistance members and getting devices and equipment from Israel for spying purposes.”