Sydney - Australia's Prime Minister Tony Abbott said on Thursday that Islamic State is worse than the Nazis were during World War II.
"The Nazis did terrible evil but they had sufficient sense of shame to try and hide it. These people boast about their evil. This is the extraordinary thing," Abbott told conservative radio host Alan Jones on Sydney's Radio 2GB.
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"They act in the way medieval barbarians acted only they broadcast it to the world with an effrontery that is hard to credit and it just adds a further dimension to this evil."
Abbott said everything possible needed to be done to defeat the "unspeakable evil of the Daesh death cult", using the name for the organisation based on its Arabic acronym.
Jewish groups upset
Abbott's Nazi comments upset Australian Jewish groups. President of the executive council of Australian Jewry, Robert Goot, said there was "a fundamental difference between organised acts of terrorism and a genocide systematically implemented by a state as essential policy".
"Whilst there is no question that Islamic State is a profoundly evil organisation, the Prime Minister's comments suggesting that it is in some respects worse than the Nazis were injudicious and unfortunate," Goot was quoted as saying by the Sydney Morning Herald.
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"The crimes of Islamic State are indeed horrific, but cannot be compared to the systematic round-up of millions of people and their despatch to purpose-built death camps for mass murder."
Abbott's comparison came as his government considers a request from the United States to expand Australia's contribution to the fight by joining aerial attacks on Islamic State positions inside Syria.
Abbott said the decision will be made next week when Defence Minister Kevin Andrews returns to the country.
The Australian air force is currently assisting international raids on Islamic State in Syria with intelligence and refuelling only.
In Iraq, it is helping with actual bombing raids, and has deployed six F/A-18F Hornet fighter-bombers, refuelling and command aircraft and 300 army instructors training Iraqi troops.
The coalition conducting airstrikes on Islamic State positions inside Iraq also include the United States, Canada, Denmark, France, Jordan, the Netherlands and Britain.
Coalition nations currently conducting airstrikes against Islamic State forces inside Syria include the United States, Bahrain, Canada, Jordan, Saudi Arabia and the United Arab Emirates.