The Mongol military was also successful in siege warfare, cutting off resources for cities and towns by diverting certain rivers, taking enemy prisoners and driving them in front of the army, and adopting new ideas, techniques and tools from the people they conquered, particularly in employing Muslim and Chinese siege engines and engineers to aid the Mongol cavalry in capturing cities. Another standard tactic of the Mongol military was the commonly practiced feigned retreat to break enemy formations and to lure small enemy groups away from the larger group and defended position for ambush and counterattack.