There were six airfields on Bougainville located in the north, the south, and along the eastern coast. Allied air operations had heavily degraded Japanese air operations and air bases around Bougainville. Consequently, aircraft of the 11th Air Fleet were withdrawn from southern Bougainville to Rabaul in October. About 200 aircraft from the 11th Air Fleet were located around Rabaul at the time of the landings at Cape Torokina. A further 173 carrier aircraft were planned to arrive in late October, in preparation for a planned air offensive as part of Operation RO. This operation envisaged severing Allied lines of communication to inflict delay on the forces advancing towards Rabaul, while the Japanese reduced and consolidated their defensive perimeter in the Southwest and Central Pacific, in consequence of a decision made in September 1943. The carrier aircraft arrived at Rabaul over the course of 1 and 2 November, arriving too late to be employed by the Japanese around Cape Torokina in the first few days of the landing. On the first day only 120 aircraft of the 11th Air Fleet were used over the landing area. The attention of the carrier aircraft at Rabaul was largely diverted away from Empress Augusta Bay on 2 November, by heavy US air attacks on Rabaul, which continued into mid-November.