Australian police believe militants were planning to blow up a plane using a home-made bomb hidden in a meat grinder in an "atrocious" plot apparently foiled after an urgent tip-off from British intelligence.
As the federal government warned yesterday that stricter security at airports would remain indefinitely, police in Sydney continued to search for evidence at five properties believed to be linked to the plot. Four men have been arrested.
According to The Australian newspaper, the plot was orchestrated by the Islamic State in Iraq and Syria (ISIS), and may have involved a bid to bring down a plane by gassing its passengers.
Police have yet to confirm precise details of the plot or the flight believed to be targeted.
Yesterday morning, police found a flight number for a Jakarta to Sydney flight in a rubbish bin at a house in the Lakemba suburb, reported the Daily Telegraph. It was not clear if this flight was being targeted.
Other reports claimed that the target was a flight to Dubai or that the plotters may have already tried to smuggle a bomb onto an international flight and had now turned their attention to a domestic route.
ABC News reported last night that Australian police wanted more time to collect evidence, but the British government had warned it would publicly declare a security alert for travel to Australia if the raids were not carried out promptly.
Federal Justice Minister Michael Keenan refused to confirm or deny the report, telling ABC's 7.30 Report: "But what we have seen is we have acted once we got information that there was something brewing within the Australian community that required our attention."
The four suspects arrested were identified yesterday as Khaled Merhi, a Sydney painter, Khaled Khayat, Mahmoud Khayat and Abdul Merhi. They are reportedly in their 30s to 50s.
Mr Keenan would not say when the men will be charged.
"It is quite a complicated investigation because the allegations are of a sophisticated plot to do what would have been an enormous atrocity," he said. "It is clear that this was inspired by radical Islamist ideology."
According to ABC News, the mastermind was Khaled Khayat, whose brother is believed to be a senior fighter with ISIS and whose son was one of the four arrested.
The federal government has introduced stricter airport screening of passengers and luggage, and signalled that the changes may be in place indefinitely. The measures have led to long airport queues, particularly in Sydney.
"The security measures at the airports will be in place for as long as we believe they need to be, so it may go on for some time yet," Federal Immigration Minister Peter Dutton told reporters yesterday. "It may be that we need to look at the security settings at our airports, in particular our domestic airports, for an ongoing enduring period."
The latest alleged plot is the 13th attempted mass-casualty terrorist attack in Australia in the past three years.
The head of the Australian Strategic Policy Institute's Counter-Terrorism Policy Centre, Ms Jacinta Carroll, said Australia faced a real threat of a mass-casualty attack, but a lone-wolf attack was more likely to succeed. "The complexities involved with attacks continue to mean they are more likely to be disrupted than the low-profile attacks of a lone actor," she wrote in The Australian yesterday.
Four arrested in alleged airplane bomb plot.