The New South Wales Joint Counter Terrorism Team has charged two men in Sydney with terrorism offences.
49-year-old Lakemba man Khaled Khayat and 32-year-old Punchbowl man Mahmoud Khayat have each been charged with two counts of acts done in preparation for, or planning, a terrorist act.
The maximum penalty is life imprisonment.
Both men are scheduled to appear at Parramatta Court on Friday morning.
On July 29 four men were arrested in relation to allegations regarding a potential terrorist attack.
A 50-year-old man was released from police custody on Tuesday without charge.
One man, Khaled Merhi, remains in police custody under "specified" time provisions, meaning he is under an extended period of detention.
Police have searched six separate premises across Sydney this week, including the suburbs of Lakemba, Punchbowl, Surry Hills, Wiley Park and Bankstown.
In a statement the Australian Federal Police said the investigation was ongoing and encouraged community members to report "suspicious activity" to the National Security Hotline on 1800 123 400.