They sprang up in the wake of the surge of the American troops across central Iraq this year which has had some success in quelling the violence in some of the most troubled regions.

• 今年，他们穿越了伊拉克的中部，紧随着美军的大部队来到这里，他们已经成功平息了伊拉克几个最动乱地区的暴力冲突。