After the Battle of the Coral Sea frustrated the Japanese plan to capture Port Morseby via an amphibious landing, the Japanese attempted to capture the town by landing the South Seas Force at Buna on the north coast of Papua and advancing overland using the Kokoda Track to cross the rugged Owen Stanley Range. The Kokoda Track campaign began on 22 July, when the Japanese began their advance, opposed by an ill-prepared CMF brigade designated 'Maroubra Force'. This force was successful in delaying the South Seas Force but was unable to halt it. Two AIF battalions from the 7th Division reinforced the remnants of Maroubra Force on 26 August, but the Japanese continued to make ground and reached the village of Ioribaiwa near Port Moresby on 16 September. The South Seas Force was forced to withdraw back along the track on this day, however, as supply problems made any further advance impossible and an Allied counter-landing at Buna was feared. Australian forces pursued the Japanese along the Kokoda Track and forced them into a small bridgehead on the north coast of Papua in early November. The Allied operations on the Kokoda Track were made possible by native Papuans who were recruited by the Australian New Guinea Administrative Unit, often forcibly, to carry supplies and evacuate wounded personnel. The RAAF and USAAF also played an important role throughout the campaign by attacking the Japanese force's supply lines and airdropping supplies to Australian Army units.