The armed opposition in Iraq are taking advantage of speed,  and coalition rules of engagement, to defeat America's high tech weapons. Several teams of Iraqis are moving around near coalition bases at night and firing a few mortar shells, then slinking away and hiding their mortar and ammunition. The weapon used is usually a Russian made 82mm mortar. This weapon weighs about 80 pounds, but can be broken down into three pieces (the heaviest weighing 29 pounds, the lightest 22). Each 82mm mortar shell weighs about seven pounds (and contains about 14 ounces of explosives). The mortar has a maximum range of about 8,000 meters. The U.S. has a Firefinder radar which, when it spots an incoming shell, calculates where it came from and transmits the location to a nearby artillery unit, which then fires on where the mortar is (or was). This process takes 3-4 minutes (or less, for experienced troops.) But there are rules of engagement to deal with. You cannot fire your artillery into a populated area. And this is where the Iraqis usually fire their mortar from; some civilians back yard. As a result, Firefinder knows where the Iraqi mortar is, but the American artillery can't fire because of the nearby civilians. However, the location of the mortar is also sent to a nearby infantry unit, which now has troops standing by to rush to the location. But the Iraqis know how this works (some got caught and the word got around.) So the Iraqi teams fire a few shells, then take their mortar apart and move away. This process takes a minute or so. Some Iraqi gunners have fired from uninhabited areas (sometimes because there were no civilian neighborhoods within range) and got blasted. But the Iraqis eventually realized that their best bet was to fire from a civilian area and then run. Fortunately, the Iraqi mortarmen have not been very skillful, and often miss large targets (covering several acres). This cat and mouse game continues, apparently with UAVs and gunships getting involved as well. So while the Iraqi "shoot and run" tactics have been fairly successful, there is still a risk, and a growing one at that, for the midnight mortar operators.