New security measures introduced after NSW terror raids

Authorities say they've foiled an alleged terrorist conspiracy to bring down a plane using an improvised explosive device.Image: Prime Minister Malcolm Turnbull speaks at the Commonwealth Parliamentary Offices in Sydney, following counter terror raids. (AAP/am Mooy)

Four men are in custody after New South Wales and Australian Federal Police officers raided properties in the Sydney suburbs of Surry Hills, Lakemba, Wiley Park and Punchbowl last SaturdayThe men are yet to be charged.