Australia's national security intelligence service said Thursday extremists from Australia who came in Syria and Iraq to fight for various exstrimist groups suffered heavy casualties during battles.
"The overall number of Australians currently fighting with or supporting Islamic extremist groups in Syria and Iraq has remained consistent over recent months," Secret Intelligence Organization (ASIO) Deputy Director-General Kerri Hartland was quoted as saying by the local Fairfax Media.
According to her, at least 20 Australians have been killed in the Middle East but more people are going and the rates of arrivals and deaths are about the same, Xinhua reported.
She said the ASIO findings indicate a comparatively high casualty rate for Australian fighters, with "the numbers of new arrivals roughly keeping pace with the fatalities."
Since the civil war erupted in Syria in 2011, thousands of fighters from Western countries of Middle East origin have joined some extremist groups to fight against Syrian President Bashar al-Assad's government.
Some of them are Australians trained on the battle field and joined the Islamic State (IS).
According to ASIO, the western jihadis also crossed border with IS into Iraq and launched wars against the Iraqi government forces, with the current number of Australian fighters remaining stable at about 70 in the two countries.