In the movie "Genghis Khan", unless it was wrong, Genghis Khan did mention that he would not kill women, children, old and weak. Does not seem to be true in his expeditions.
E.g. "On another occasion, Mongols rounded up 70,000 men, women and children, and shot them with arrows. Genghis told his comrades: “Man’s greatest good fortune is to chase and defeat his enemy, seize his total possessions, leave his married women weeping and wailing, ride his gelding, use his women as a nightshirt and support, gazing upon and kissing their rosy breasts, sucking their lips which are as sweet as the berries of their breasts. ”
http://listverse.com/2011/04/17/10-more-evil-men/