▁Christmas ▁Hills ▁until ▁rel ieved ▁by ▁elements ▁of ▁the ▁ 4 th ▁Brigade , ▁which ▁pushed ▁the ▁Australian ▁advance ▁along ▁the ▁coast , ▁forcing ▁the ▁Japanese ▁north ▁towards ▁S io ▁as ▁the ▁Austral ians ▁sought ▁to ▁secure ▁the ▁Hu on ▁Pen ins ula . ▁In ▁late ▁December , ▁the ▁ 2 0 th ▁Brigade ▁rot ated ▁back ▁into ▁the ▁lead , ▁and ▁the ▁ 2 / 1 5 th ▁took ▁over ▁from ▁the ▁ 2 2 nd ▁Battalion ▁around ▁the ▁Tun om ▁River , ▁where ▁the ▁batt alion ▁headquarters ▁came ▁under ▁aer ial ▁attack . ▁After ▁a ▁brief ▁pause ▁near ▁the ▁flo od ▁sw ol len ▁Tun om , ▁the ▁advance ▁continued ▁throughout ▁December ▁and ▁into ▁January ▁ 1 9 4 4 ▁with ▁minor ▁sk irm ishes ▁pun ctu ating ▁the ▁batt alion ' s ▁advance . ▁Finally , ▁on ▁ 2 1 ▁January , ▁at ▁the ▁edge ▁of ▁the ▁S az om u ▁River , ▁the ▁order ▁arrived ▁for ▁the ▁ 2 / 1 5 th ▁to ▁be ▁with dra wn ▁to ▁Fin sch h afen ▁for ▁rest ▁prior ▁to ▁rep atri ation ▁to ▁Australia . ▁The ▁fighting ▁in ▁New ▁Guinea ▁cost ▁the ▁batt alion ▁ 3 0 ▁killed ▁in ▁action , ▁six ▁dead ▁from ▁w ounds , ▁four ▁dead ▁from ▁acc idents ▁and ▁ 1 1 9 ▁wounded . ▁ ▁The ▁ 2 / 1 5 th ▁Battalion ▁returned ▁to ▁Australia ▁in ▁mid - M arch ▁ 1 9 4 4 ▁ab o ard ▁the ▁K lip f onte in .