The Japanese weren't very discriminative in the women they raped: girls as young as seven and women approaching one hundred were brutally raped, sometimes by multiple soldiers at once and on repeated occasions. In some cases, the Japanese soldiers seized the women and held them prisoner in order to continue raping them whenever they wanted.
These rapes weren't committed in privacy, instead being performed in public, where the families of the women were forced to watch or even participate. The Japanese officials ordered the soldiers to murder the women when the soldiers were done with them, a practice most performed by cutting off the women's breasts or disemboweling them. Even the most senior of officers participated in these atrocities.
After continuously gang raping a pregnant Chinese woman, the soldiers murdered her and cut off her fetus. The fetus was presented to their commander on a bayonet, evoking no small amount of laughter from the officer.