on Buin, on the southern tip of Bougainville, instead of the Cape Torokina – Empress Augusta Bay area. Operation The Allies launched the invasion of the Treasury Islands at 06:06 hours on 27 October. Three echelons of high speed transports (APDs), totalling eight vessels, were assembled for the operation. In addition, there were eight LCIs; two LSTs and three LCTs allocated. Several minor reconnaissance operations were undertaken prior to the landing, firstly on 22–23 August and then 21–22 October. Meanwhile, the assaulting force conducted rehearsals off Florida Island in the lead up. Commencing on 27 October, following a short naval and aerial bombardment, seven APDs arrived in the transport area west of Cummings Point on Stirling Island and began disgorging their smaller landing craft, which were assigned to land forces on either side of the harbour. Despite heavy rain, which reduced visibility, the destroyers and laid down a heavy, but ultimately ineffective pre-landing bombardment. Following this, two infantry battalions – the 29th and 36th – landed around Falamai, on the southern coast of Mono Island, approximately away from Blanche Harbour's western entrance. Meanwhile, a detachment from a third infantry battalion, the 34th, landed on Stirling Island, to the south of Mono, while another detachment of 200 personnel from the 34th, supported by the APD , skirted around the western side of the island and landed to the north around Soanotalu, to provide security for a radar station that would be installed there. A total 3,795 men landed in the assault wave with the remainder of the Allied force landing in four waves during the following 20 days, to reach a total of 6,574 men. The operation was the first amphibious assault launched by New Zealand troops since the Gallipoli Campaign in 1915. It was the second combat operation undertaken by the New Zealanders in the Pacific, following the Land Battle of Vella Lavella, which had taken place the previous month. The New Zealand infantry were supported by US combat support and service support units including a naval construction battalion (the 87th), a signals unit, a naval base unit, and a coastal artillery battalion (the 198th) to provide anti-aircraft fire support. The Japanese were caught by surprise and were unable to scramble aircraft to attack the assault craft until after the troops had landed. Subsequently, late on 27 October, a force of 25 dive bombers attacked two US destroyers, and .