On April 11, Japanese troops retook Lengkou Pass after dozens of seesaw fights over the pass defenses and Chinese forces at Jielingkou abandoned that pass.[3] The Chinese army was significantly underarmed in comparison to the Japanese and many units were equipped with predominantly with handguns, hand grenades, and traditional Chinese swords with limited supplies of trench mortars, heavy machine guns, light machine guns and rifles. Beaten back by overwhelming Japanese firepower, on May 20, the Chinese army retreated from their remaining positions on the Great Wall.