 The Japanese had established strong defences along the river's southern bank, which the Australians attempted to outflank by sending a force to the west, climbing through steep terrain.Once they had located a suitable place to cross the river, they began wading across but were fired upon by a group of Japanese naval infantry who were positioned on a high feature overlooking the river.Despite taking casualties, the Australians were able to establish themselves south of the Bumi and at that point the 2/13th Infantry Battalion began to advance on Finschhafen from the west.