The perceived threat of invasion led to a major expansion of the Australian military. By mid-1942 the Army had a strength of ten infantry divisions, three armoured divisions and hundreds of other units. The RAAF and RAN were also greatly expanded, though it took years for these services to build up to their peak strengths. Due to the increased need for manpower, the restrictions which prohibited non-Europeans from joining the military ceased to be enforced from late 1941, and about 3,000 Indigenous Australians eventually enlisted. Most of these personnel were integrated into existing formations, but a small number of racially segregated units such as the Torres Strait Light Infantry Battalion were formed. A number of small units made up of Indigenous Australians were also established to patrol northern Australia and harass any Japanese forces which landed there; the members of these units did not receive pay or awards for their service until 1992. Thousands of Australians who were ineligible for service in the military responded to the threat of attack by joining auxiliary organisations such as the Volunteer Defence Corps and Volunteer Air Observers Corps, which were modelled on the British Home Guard and Royal Observer Corps respectively. Australia's population and industrial base were not sufficient to maintain the expanded military after the threat of invasion had passed, and the Army was progressively reduced in size from 1943 while only 53 of the 73 RAAF squadrons approved by the government were ever raised.