GAZA CITY, Gaza Strip (AP) — Gaza militants Friday gunned down 18 alleged spies for Israel in an apparent attempt to plug security breaches and deter others, a day after Israel killed three top Hamas military commanders in an airstrike likely guided by collaborators.

In one incident, masked gunmen lined up seven men, their heads covered by bags, along a wall outside a Gaza City mosque and shot them to death in front of hundreds of people, witnesses said. A note pinned on the wall said they had leaked information about the location of tunnels, homes of fighters and rockets that were later struck by Israel.