Later in the Vietnam War, Vietcong and North Vietnamese soldiers assigned elite sappers to stealthily penetrate defenses of sites controlled by enemy forces. Often, this meant using satchel charges as well as Bangalore torpedoes to blast through barbed wire entanglements, minefields, structures, and other fortifications. The later U.S. M183 Demolition Charge Assembly contained of C-4 in each satchel, and could be used with a timed fuse. In the Second Battle of Fallujah in Iraq, U.S. M2 20 lb assault demolitions were used to collapse houses being used as fighting positions by insurgents.