 Although the main focus of Australia's military during World War I was overseas in Europe and the Middle East, there was still a necessity to maintain troops in Australia on home service to carry out a number of essential tasks.As the AIF was otherwise engaged these duties out of necessity fell to the soldiers of the militia and a small number of regular soldiers.In the early stages of mobilisation a number of militia infantry battalions were called out to carry out guard duties upon infrastructure that was considered important to the war effort, such as munitions factories, communications facilities, ammunition dumps and transportation centres.