A young man has been charged with planning a terrorist act after an incident in a shopping centre where he was allegedly seen throwing bottles of chemicals into a bathroom.
Emergency services were called to Miranda Westfield, in Sydney's south, following reports of a man throwing bottles just after 2pm on July 24.
Officers established a number of crime scenes and seized several bottles for forensic examination.
A 21-year-old man was arrested nearby and police said they found him carrying a knife and a bottle.
Witnesses reported hearing the sound of a small explosion inside the shopping centre at the time of the incident.
The man was charged with possession of a non-firearm for discharging an irritant in a public place, custody of a knife in a public place and leaving or sending a substance to create a false belief of danger.
Officers said they later found and seized chemicals, electronic devices and mobile phones during a search of a nearby Loftus home.
Two further Commonwealth charges were laid in Sutherland Local Court on Thursday following investigations by officers with the NSW Joint Counter Terrorism Team.
The charges include knowingly collecting or making a document connected with terrorism and doing an act in preparation or planning for a terrorist act.
Police will allege the man had "mixed and unclear ideological beliefs".
The man remains on remand and will next appear at Downing Centre Local Court on September 25.