SYDNEY • The foiled terrorist plot to attack high-profile locations in Melbourne was inspired by ISIS and the suspects had been under close surveillance for two weeks, said Acting Victorian Police Commissioner Graham Ashton.
He said those detained allegedly planned to use explosives, knives and guns to attack busy locations, including Melbourne's Flinders Street train station, Federation Square and St Paul's Cathedral.
"Over the last fortnight... we have had to conduct a criminal investigation relating to the formation of what we believe was a terrorist plot," he told reporters yesterday.
"We believe that there was an intention to conduct what we call a multi-mode attack, possibly on Christmas Day," he said, adding that the threat had been removed "in its entirety".
"The attack that we will allege was being planned, we believe was going to involve an explosive event, the use of explosives, and we gathered evidence to support that."
Police believe the plotters were planning to also use other weapons, including knives and guns.
The targets of the alleged attack are all in the same area in the heart of the city, and only a short distance from the Melbourne Cricket Ground, where up to 100,000 people are expected to attend the Boxing Day Test between Australia and Pakistan.
Of the seven - six men and a woman - arrested yesterday morning, two, including the woman, were released without charge. Four have been charged.
Police in Australia are able to hold terror suspects without charge for four hours, but they can also apply to a court to detain them without charge for as long as two weeks.
Commissioner Ashton said four of those detained were Australian- born, of Lebanese descent, with the fifth an Egyptian-born Australian citizen, all in their 20s.
"Certainly they are self-radicalised, we believe, but inspired by ISIS and ISIS propaganda," he added, referring to the Islamic State in Iraq and Syria militant group. "If this had got under our guard, this would have been a significant attack, we believe. No doubt about that."
He added: "A substantial number of people could have been injured in the attack, from what we have seen. Certainly potential for quite a number of people to be injured or killed in this attack."
The foiled plot comes amid security on heightened alert in Australia after a truck drove into a Christmas market in Berlin, killing 12 people in an attack claimed by ISIS.
Security forces across Asia, including in Indonesia, Malaysia and Singapore, were also on alert yesterday ahead of the Christmas and New Year holidays.
Australian Prime Minister Malcolm Turnbull said a potential disaster had been averted in Melbourne, and praised police and security services.
"This is one of the most substantial terrorist plots that have been disrupted over the last several years," Mr Turnbull said in Sydney.
"We are approaching the Christmas season, a time when we come together in peace and love, with our families.
"These terrorists sought to disrupt it. They have been thwarted. They are in custody. They are no longer a threat to Australians' security."
The Australian authorities have said they have thwarted a number of terrorist plots, particularly involving radicalised teenagers, in recent years.
There have also been several "lone wolf" assaults, including a 2014 cafe siege in Sydney. Two hostages and the gunman were killed.
AGENCE FRANCE-PRESSE, REUTERS