Australian police have said a set of twin terror plots - one targeting a flight and the other a potential poison gas attack - are the "most sophisticated" incidents the country has ever dealt with.
Two men in Sydney - 32-year-old Mahmoud Khayat and 49-year-old Khaled Khayat - were charged with offences relating to terrorism on Thursday (August 3).
One of the plots reportedly involved an attempt to place an improvised explosive on an Etihad Airways flight leaving Sydney.
One of the men - Khaled - attempted to have his brother take it onto the flight, his sibling having no knowledge of the explosive in the bag.
However, for a reason which remains unclear, the bag never made it past the check-in desk.
The other plot is reported to have been a plan to release poison gas in a public area, but it reportedly failed because the two were unable to create the toxin.
Australian authorities said a senior Isis commander had sent the parts for the explosive by air cargo from Turkey, and called it the "sophisticated terror plot" to occur on Australian soil.
Both suspects made an appearance at Sydney's Parramatta Court on Friday, but no plea has been entered and no bail arrangements will be made until a brief of the evidence is presented.