Five face charges over plotting Sydney terror attack

Five people are facing terrorism charges as part of an ongoing investigation into an alleged plot to attack a Australian government building in Sydney.

Australian Federal Police deputy commissioner of national security Michael Phelan said a 15-year-old and 20-year-old man from western Sydney were arrested and charged with conspiracy to prepare for a terrorist act.

Three other people who are already jailed on other terror charges will be charged with the same offence later on Thursday.

Officials said the arrests were not related to a new terror threat, but linked to a plot they previously uncovered that prompted a series of raids in Sydney in December 2014.

That alleged plot involved a plan to target a government building in the city.