Australian Islamic State fighters doubled last year

Australian Foreign Minister Julie Bishop, pictured at the United Nations Headquarters in New York, on July 29, 2015.

Sydney (AFP) - The number of Australians fighting for the Islamic State group in Syria and Iraq doubled in the past year but was not expected to continue to grow so rapidly, Foreign Minister Julie Bishop said.

Australia has been increasingly concerned about the ability of IS, also known as Daesh, to lure citizens to the conflict and at least 20 nationals are believed to have died there.