Police disrupted the first alleged plot in Australia to bring down an airplane and arrested four men in raids on Sydney homes, officials said Sunday.
Prime Minister Malcolm Turnbull said that security has been increased at Sydney Airport since Thursday because of the plot. The increased security measures also were extended to all major international and domestic terminals around Australia overnight, ABC News reported.
“I can report that there has been a major joint counterterrorism operation to disrupt a terrorist plot to bring down an airplane last night,” Turnbull told reporters. “The operation is continuing.”
Australian Federal Police Commissioner Andrew Colvin said details were scant on the specifics of the attack, the location and timing.
“In recent days, law enforcement has become aware of information that suggested some people in Sydney were planning to commit a terrorist attack using an improvised devise,” Colvin said.
Deakin University security expert Greg Barton said the first plot to target aircraft in Australia, which is the highest aspiration of many extremists, was a “pretty big threshold moment.”
The plotters were apparently making a peroxide-based explosive device rather than using nitrate-based chemicals that can be detected by airport security swab tests, Barton said.
The plan most likely was to take the explosive on board in carry-on luggage unless there was a baggage handler involved who could ensure that a stowed bomb exploded near the fuselage where it would be most damaging.
Seven Network television reported that 40 riot squad officers wearing gas masks stormed an inner-Sydney house before an explosives team found a suspicious device. Colvin declined to say whether a fully equipped improvised explosive device had been found at that address.
None of the four suspects arrested in five raids had been charged, Colvin said. He would not discuss what charges they might face. None of the arrested men worked in the airport industry, Colvin said.
Australia’s terrorist threat level remained unchanged at “probable,” Turnbull said. He advised travelers in Australia to arrive at airports earlier than usual — two hours before departure — to allow for extra security screening and to minimize baggage.
