The entry of Italy into the war was followed by the large-scale internment of Italians, especially in Queensland, South Australia and Western Australia. The concern in Queensland was that Italians would somehow join forces with an invading Japanese force and constitute a fifth column. Between 1940 and 1945, most of those who had not been naturalised before the war's outbreak were considered "enemy aliens", and therefore either interned or subjected to close watch, with respect to personal movements and area of employment. There were many cases of Italian-Australians who had taken out Australian citizenship also being interned. This was particularly the case in northern Queensland.