Australian to be awarded the medal during the Second World War, and was also the youngest. Elsewhere, the Australians continued to mount patrols and ambushes. On 29 July, a platoon from the Papuan Infantry Battalion (PIB) clashed with a similar sized force of Japanese around the junction of the Ratsua Road–Umum Track. Two days later, after the PIB had assumed a flank security role on the eastern side of the peninsula, another patrol clashed with a party of Japanese who had been attempting to set up an ambush near Ruri Bay. In the ensuing fight, 14 Japanese were killed; a further 20 were killed in a firefight around the same area on 7 August. Meanwhile, on 2 August, a patrol from the 27th Infantry Battalion was sent out along the Ruri Bay Road in company with two tanks that were to act as their direct fire support. The Japanese were still active in the area, and had mined the road with a bomb that they had rigged to be detonated remotely. The Australian patrol accidentally triggered the device and the resulting explosion killed three men in one of the tanks and wounded eight infantrymen following behind. On 5 August, the Australians reoccupied the position at Base 5 after encountering only slight resistance and subsequently named it "Part Ridge". After exploiting the position, it was discovered that the Japanese had built between 43 and 60 bunkers in the area. The majority of these had been destroyed by artillery, though, and after the area had been thoroughly searched for Japanese stragglers, the Australian patrol was withdrawn from the ridge. Aftermath The fighting around Base 5 was the final action of the fighting in the northern sector of the island, which essentially ended in stalemate. The Australians, under pressure to limit casualties to their largely inexperienced troops, had pursued a cautious campaign and had been slow to regain the initiative in the area following the defeat at Porton Plantation. In contrast, the Japanese commander—Kato—had been skillful and aggressive. On 11 August, in anticipation of the capitulation of Japan following the dropping of two atomic bombs on Japanese cities, the order to cease offensive combat operations on Bougainville was passed to all Australian units by their commanders. Three days later, on 15 August, the Japanese Emperor Hirohito publicly announced Japan's unconditional surrender, effectively bringing about an end to the war. On 18 August, in