Aug. 4 (UPI) -- Australian police on Friday detailed a foiled terrorist plot to blow up a commercial airliner, saying it was one of the most sophisticated they've seen yet.
Two brothers were arrested on charges of preparing or planning a terrorist attack and will be arraigned on Friday. Investigators said they planned to smuggle a bomb they had constructed from of parts -- sent to them by the Islamic State terror group -- onto an Etihad Airlines plane flying out of Sydney.
Khaled Khayat, 49, and Mahmoud Khayat, 32, appeared via video link in a Sydney court on Friday. Their next hearing is scheduled for Nov. 14. Both could receive life imprisonment if convicted.
The bomb was discovered at the airport's check-in counter on July 15 before it made it onto the plane, authorities said.
Australian Federal Police Deputy Commissioner Michael Phelan called the plan "one of the most sophisticated plots that has ever been attempted on Australian soil," noting that the two suspects constructed and concealed a "high-end" explosive device.
Phelan added that one of the suspects was instructed by an Islamic State official how to assemble the bomb into an IED -- or improved explosive device -- for the flight.
"As a result of that aborted attempt, there were a number of actions that took place on that day, and we did recover components of that IED," he said.
Police said the plan called for one suspect to unknowingly carry the bomb aboard the flight.
After the plot failed, the brothers attempted to construct a less sophisticated chemical device of hydrogen sulfide. Investigators said they were again advised by IS operatives on which public places they should place the chemical device, but "were a long way from" completion.
Police and intelligence officials arrested four more people suspected of connections to the plot last weekend.