"The use of the rocket-propelled bombs reflects militiamen's ability to use commonly available materials and relatively low-tech weaponry to circumvent security measures that have cost the U.S. military billions of dollars. To combat roadside bombs, known as improvised explosive devices or IEDs, U.S. and Iraqi troops have set up scores of checkpoints throughout the capital, increased patrols and purchased hundreds of armored vehicles that can resist such attacks.
A June report on the Web site Long War Journal called the explosives-filled propane tanks "flying IEDs."
Militia members and insurgents have at times increased the sophistication of their weapons, but the rocket-propelled bombs are makeshift devices that also have been used in recent years by insurgents in Colombia. Propane tanks are ubiquitous in Iraq, where the fuel is widely used for cooking, making it hard for security forces to stop production of the bombs. "
