Air support was provided by No. 9 Operational Group RAAF, which included several Royal Australian Air Force squadrons such as No. 4 Squadron RAAF, flying CAC Boomerangs and Wirraways, and No. 24 Squadron RAAF equipped with Vultee Vengeance dive bombers; these units undertook numerous close air support and resupply missions throughout the campaign. American Republic P-47 Thunderbolts and Lockheed P-38 Lightnings from the 348th and 475th Fighter Groups were also used to provide fighter cover for Allied shipping, while heavy and medium bombers from the Fifth Air Force carried out strategic bombing missions to reduce Japanese airbases around Wewak and New Britain, and raided Japanese lines of communication in concert with PT boats. Due to the impracticalities of using wheeled transport in the jungle, Allied logistics was undertaken primarily by means of water transport such as landing craft and barges which moved supplies along the coast, with overland supply to combat units being completed by New Guinean labourers and, at times, by Australian combat troops themselves, which were re-roled temporarily to undertake portage tasks as required, and augmented where possible with jeeps.