having previously served in North Africa, the Middle East and New Guinea. Prior to the Borneo campaign, the division had been resting and reorganising on the Atherton Tablelands in Queensland. The division had experienced a high turn over in personnel following its service in the Huon Peninsula campaign as soldiers were medically discharged or transferred to other units. In addition to the Australian ground troops, naval support was provided by the United States Navy and Royal Australian Navy and aerial support from the United States Army Air Force's Thirteenth Air Force, the United States Marine Corps, and elements of the Royal Australian Air Force's 1st Tactical Air Force. Two United States Army units, the 727th Amphibian Tractor Battalion who manned the LVTs and the 593rd Engineer Boat and Shore Regiment's Boat Battalion, were also attached to the Australians. Meanwhile, Allied intelligence estimated that there were approximately 31,000 Japanese troops on Borneo, with about 8,800 of these in North Borneo. The Japanese Thirty-Seventh Army, led by Lieutenant-General Masao Baba, was tasked with defending the area, and was headquartered in Jesselton. The main Japanese units in the vicinity included elements of the 56th Independent Mixed Brigade, consisting of six battalions (the 366th to the 371st), along with another independent battalion. This brigade was commanded by Major General Taijiro Akashi. It had been raised in Japan during the second half of 1944 and arrived in Borneo late that year as the area's garrison troops were reorganised for defence against future Allied landings. By mid-1945, the brigade had been heavily depleted by its overland movement from the north-eastern part of Borneo prior to the Allied landings and was at around half strength; its troops were largely inexperienced, lightly equipped and were suffering from poor morale. Japanese air power in the region had been heavily depleted and, except in Java and Sumatra, was ineffective, although there were small numbers of aircraft at Keningau and Kuching. Battle Labuan Two main landings were undertaken by the Australians in North Borneo on 10 June. After concentrating at Morotai Island in May, where complex landing rehearsals were undertaken, the assault force, consisting of 85 ships—mainly from the US Navy—departed in early June, preceded by minesweepers and survey vessels, as well as the naval attack group. The first landing was made when troops from two battalions of Brigadier Selwyn Porter's 24th Brigade—the 2/28th and 2/43rd Battalions—landed on Labuan Island with