Australian police arrested four terrorists in a raid and disrupted an allegedly Islamist-inspired "terrorist plot" to bring down an airplane with an improvised explosive in Sydney.
Australian Prime Minister Malcolm Turnbull said, "I can report last night that there has been a major counter-terrorism operation to disrupt a terrorist plot to bring down an airplane." Additional security has been put in place at all major domestic international airports, with travelers told to arrive two hours early for screenings, he added.
The four men arrested in a series of raids across Sydney on Saturday, were allegedly linked to an "Islamic-inspired" plot said Australian Federal Police Commissioner Andrew Colvin said. But still, police doesn't have "a great deal of information on the specific attack, the location, date or time," with the investigation expected to be "very long and protracted."
In recent days, law enforcement have become aware of information that suggested some people in Sydney were planning to commit a terrorist attack using an IED (improvised explosive device)," he added.
The plot was the 13th significant threat disrupted by police since Australia's terrorist threat level was elevated in 2014, Justice Minister Michael Keenan said. Five plots have been executed.
Turnbull said that the national terror alert would remain at probable although this alleged IS plan seemed to be "more in that category of an elaborate plan" rather than design by a lone wolf.
Despite the high security and stopped plans, several attacks have taken place, including a cafe siege in 2014 where two hostages were killed and the murder of a sydney police employee in 2015 by a 15-year-old boy.