Twin terror plots, one involving the bombing of a passenger plane and the other a potential poison gas attack, have been described by police as the “most sophisticated” ever attempted on Australian soil.

A senior ISIS commander sent parts — including weapons-grade explosives — by air cargo from Turkey with the express aim of constructing an improvised explosive device (IED), said Australian Federal Police Deputy Commissioner National Security Michael Phelan during a press conference Friday.
The other scheme involved a plan to release a toxic gas in public, but was foiled due to the accused being unable to produce the deadly gas.
Two men living in Sydney, identified by CNN affiliate Seven News as Khaled Khayat, 49, from Lambeka, and Mahmoud Khayat, 32, from Punchbowl, were charged with terror-related offenses Thursday.
The two appeared by video link in Sydney’s Parramatta Court Friday and pleaded not guilty to the charges. Neither man applied for bail and the court hearing has been deferred until November 14, after a brief of evidence was requested.
“At the moment, all I can say is they are entitled to the presumption of innocence,” their legal representative, Michael Coroneos told CNN affiliate Sky News Australia. “Once the brief of evidence is served, we can assess their legal position.”
One other man remains in police custody.
After the foiled plan to down the plane was revealed Saturday, authorities described it as an Islamist-inspired plot, but did not link the plan to a specific terrorist group until Friday.

Four arrested in alleged airplane terror plot
Four suspects were arrested in Sydney on Saturday accused of planning an attack using an improvised explosive device (IED). One man was released on Tuesday and another remains in custody