MOSCOW (Sputnik) – The Joint Counter Terrorism Team (JCTT) carried out the arrests as part of Operation Appleby, launched in September 2014.
"A 20-year-old Raby [suburb] man and a 15-year-old male from Georges Hall were arrested at their homes this morning, and then later charged with one count each of conspiracy to conduct an act in preparation for a terrorist act," the police said.
The charges are said to relate to material seized during search warrants conducted a year ago.
Both unnamed terror suspects are due to appear in court later on Thursday, the juvenile in a local children’s court.
The two arrests bring the tally of terror charges as part of Operation Appleby up to 11, AFP and NSW police added.
The operation was launched after a senior Daesh jihadist group fighter from Australia warned of public beheadings across the country.
Australian Foreign Minister Julie Bishop estimated this fall that around 120 Australians were in Iraq and Syria fighting alongside the notorious terrorist organization.