 Complete the following phrase:  An advance to the Wareo-Gusika line then began, with 9 Platoon moving forward to occupy North Hill, while 10 Platoon supported the 26th Brigade by conducting probes to the Song River and Fior village to the north. The Song River was the main obstacle in the way of the Australian advance and prior to withdrawing the Japanese had destroyed the only bridge across it, requiring an alternative to be found. 10 Platoon then supported the 215th Battalion to capture Nongora, which finally fell on 2 December after heavy fighting. With the Japanese in full retreat towards Wareo, C Company PIB was tasked with cutting them off. Section from 10 Platoon worked with the 24th Commando Squadron, while 9 Platoon conducted harassing operations to the west near Joangeng. On 6 December 9 Platoon initiated a successful ambush north of Gusika, killing six Japanese. However, Gores men had been in action for over three months and as a consequence C Company was ordered to be relieved by A Company, PIB before moving to the KulungtufuHube area for rest. Meanwhile, commencing on 3 December, the Australian 4th Brigade began its advance up the coast from Gusika, leading the opening phase of the Australian 