Many of these have come through New Zealand also.
“The London-based International Center for the Study of Radicalization and Political Violence reports that between 100 and 250 Australians have joined Sunni militants in Iraq and Syria. Given Australia’s vast distance from the region and its population of just 24 million, it is a remarkable number. The center estimates that about 100 fighters came from the United States, which has more than 13 times as many people as Australia.
Experts disagree about why the Islamic State group has been so effective recruiting in Australia, which is widely regarded as a multicultural success story, with an economy in an enviable 24th year of continuous growth.”
Australia a puzzling hotbed of Islamic State recruiting