Six American soldiers were killed by roadside bombs over the weekend. It's believed that this is just a spike in the casualties. Bad luck. The battle of wits between troops and bombers has been going on with increasing intensity. The bombers have been very frustrated, seeing dozens of their carefully constructed bombs discovered and destroyed for every one that killed or wounded any Americans. The bombers have a growing catalog of ways to disguise bombs along the side of the road, and how to arrange them. Multiple bombs, arranged in increasingly complex patterns, are more common. This is making life a lot more stressful for the people organizing convoys and trying to keep the roads safe. These troops have to memorize a growing list of "things to watch for because they might be bombs." With a growing number of Iraqi police on the job, the chances are increasing that the bomb makers will get caught. But there are a lot of bomb makers, and that is unusual. The roadside bomb campaign has become a major cause of coalition casualties only because Iraqis secret police and intelligence services had a large number of people already trained to make these kinds of bombs. Most of the bomb makers are Sunni Arabs living in areas that can still muster a crowd for a pro-Saddam demonstration. This complicates police work. But until the bomb makers are rounded up, the bombs will continue to get placed, and a percentage of them will get used.