Early reports indicate the bombs that exploded in Boston Monday afternoon may have been packed with ball bearings which blew through the air like hundreds, if not thousands, of bullets being fired from as many guns.
These types of bombs are tools of warfare, and they are a variant of the kinds of Improvised Explosive Devices (IEDs) used to target U.S. troops in Iraq, Afghanistan, and elsewhere.
Palestinian terrorists have detonated similar bombs in busy shops in Israel with the aim of causing maximum casualties.
These types of bombs contain a powerful explosive around which are packed projectiles–in this case, ball bearings, allegedly–but they can be packed with nails, marbles, shards of thick glass, or even brass plates, among other things.
Some of the bombs being used against coalition forces in Iraq toward the end of that war were made by putting explosives at the end of a pipe eight or so inches in diameter and two feet long (or longer). Two or three brass plates were put inside the pipe to rest on top of the explosives at the base of the pipe. That way, when the explosives went off, the plates would become molten and blow out the open end of the pipe at passing U.S. Humvees like a bullet from a gun.
These were directional, inasmuch as they were detonated when a target was in line with the open end of the pipe.
The bombs which were detonated in Boston do not appear to have been directional. Rather, they appear to have been the kind of IED where ball bearings–or what appears to be ball bearings–are packed around explosives and wrapped or packaged tightly so as to be under pressure. Reports indicate they were then placed in trash cans and would have been detonated remotely at the time of the bomber’s choosing or at a moment preset by a timer on the IEDs.
The means of detonation will be discovered by analysts investigating the scene of the terror attack.