Australian police claim to have thwarted an Islamic State-inspired plot to attack police officers during a World War One memorial event.
Anti-terror officers in Melbourne revealed they had arrested five teenagers in a series of early morning raids no homes in the city of Melbourne.
The men, all aged between 18 and 19, are suspected of plotting to use 'edged weapons' to attack police during the city's tribute to the Australian and New Zealand Army Corps (ANZAC) landings at Gallipoli during World War One.
Saturday marks the centenary of the landings and there are huge events taking place throughout the country.
Senior police officials said they were confident the threat had been contained through their work, codenamed Operation Rising, but gave few details of the plan.
Officers would only reveal that the initial target was police officers and while they referred to the use of "edged weapons", police stressed they had no evidence to suggest there was a plot to behead anyone.
It clearly took inspiration from the Islamic State movement, also known as ISIS, Acting Deputy Commissioner Neil Gaughan of the Australian Federal Police said.
He told a news conference in Melbourne that the plan targeted "ANZAC Day activity in Melbourne which included targeting police officers".
ANZAC Day, April 25, is an major annual holiday in Australia and New Zealand marking the date of the first Gallipoli landings in 1915, in which large numbers of Australian and New Zealand troops fought and died.
The run-up to this year's centenary has been marked by numerous television programmes about the campaign, fought against the Muslim Ottoman Empire in what is now western Turkey.
After news of the plot broke, Tony Abbott, the Australian Prime Minister called on members of the public to attend all memorial events as they had previously planned.
He said: "The best thing we can do to counter terrorism... as individuals is to lead normal lives."
Concerns have risen in recent weeks that Islamic State militants might use the anniversary to carry out attacks on Australian targets.
Around 200 police officers were involved in the raids in Melbourne, Gaughan said, and enquiries were ongoing.
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Police said the alleged plot could have been executed any time in the next week.
One of the men, Sevdet Besim, appeared in Melbourne Magistrates Court where he was charged with conspiring to commit a terrorist act.
It has been revealed that a second man held on terrorism-related offences, who has not been named, is also likely to be charged.
A third man, also 18, was arrested on weapons charges and two other teenagers, aged 18 and 19, were in custody and assisting with inquiries.
All five men are from suburbs in the city's far southeast.
Australia has recently sent hundreds of soldiers to Iraq to help train forces fighting the Islamic State.
Australians have been recruited to both sides of the conflict, and some have been killed, despite a government ban on Australians fighting on either side.