A large-scale security operation is under way in Sydney
Australia's Prime Minister has confirmed that police have disrupted what they believe was a terrorist threat to bring down a plane.
A large-scale security operation is under way in Sydney where four men have been arrested.
Additional security has been put in place at all domestic and international airports in Australia.
Prime Minister Malcom Turnball says police have raided several addresses and made substantial seizures:
Mick Fuller is the police commissioner for New South Wales. He says they are not taking any chances: