A lob bomb is a type of improvised explosive made by packing a large metal canister with explosives and shrapnel, and then propelling it with the assistance of a rocket. Lob bombs are highly effective, and extremely efficient. Because they are easy to make, they are a major concern for many military leaders, who are concerned about the potential devastation which can be caused by lob bombs.
Lob bombs, known as an Improvised Rocket-Assisted Mortars (IRAMs) in military jargon, were first more widely reported during the Iraq War of the early 21st century. In this war, the first lob bombs seemed to first appear in Baghdad in 2007, fired by Shiite insurgents. While the initial lob bombs were not terribly effective, it became readily apparent that insurgents would perfect the method, potentially creating weapons which could pose a serious threat, especially when combined with other improvised explosives.
A typical lob bomb is made from a propane tank or welding tank which is drained of fuel, sawed open, packed, and then welded shut again. In some cases, the lob bomb is simply tossed off the side of a truck, without any rockets to propel it, in which case insurgents must get very close to their target. In other instances, rockets or a remote detonator are used, allowing people to target a site from a distance.
Like other improvised explosives, the lob bomb is cheap to make, and frustratingly hard to track down. Plenty of people have entirely legitimate reasons to carry around welding and propane tanks, especially in a country where propane is the major source of fuel for heaters and stoves, and it is not logistically possible to stop everyone carrying such a tank. The very cheapness of the lob bomb means that insurgents can construct a large number of such bombs, and they may not worry about duds or poorly constructed bombs, which can sometimes be even more dangerous than functioning bombs.
As with other weapons developed by insurgents in the Iraq War, the lob bomb represents a creative use of available materials, along with a serious threat. Insurgents also use the experiences of previous lob bomb attacks to refine the design, seeking out the most effective and most devastating incarnation for the lob bomb while also seeking out better targets. The explosive power of the lob bomb makes it especially ideally suited to more heavily fortified areas and structures, such as those used to protect key government and military officials.