A 20-year-old Campbell man has been charged over an alleged plot to disrupt a major defence conference at the Hyatt Hotel in Yarralumla by throwing a lit incendiary device into the venue.

The man was arrested after the ACT Joint Counter Terrorism Team (JCTT) searched homes in Campbell and Scullin on Thursday. Various items were seized and are undergoing forensic examination.

He has been charged with acting with intent to cause public alarm and damaging property. Each offence carries a maximum penalty of 10 years’ imprisonment.

Police allege rocks and an incendiary device were thrown through windows of the Hyatt Hotel on Commonwealth Avenue about 9am on Wednesday. The incident caused minor property damage and no injuries were reported.

The AFP Bomb Response Team seized the device and forensic examinations are ongoing.

About 12pm the same day, police searching the hotel located unattended backpacks in a conference room. Occupants were moved to another part of the building while the bags were assessed. By 12.30pm the items were deemed not suspicious and their owners were identified.

Police will allege the attack was intended to cause panic and fear among conference attendees.

AFP Assistant Commissioner Steve Nutt said the investigation was continuing and further charges had not been ruled out.

“Let me be clear – this was not a prank. This was an extremely dangerous act we allege was intended to, and did, have a chilling effect on conference attendees, as well as staff and other guests of the hotel,” he said.

“We will not tolerate criminal behaviour or actions which advocate hatred, fear, violence and humiliation, and attempt to erode Australia’s social fabric.

“Those allegedly involved are now the focus of our joint counter terrorism investigators, and their skills and dogged determination.”

The ACT JCTT – comprising the AFP, ACT Policing and ASIO – is continuing to investigate and is seeking to identify other people allegedly involved.

Information can be provided to the National Security Hotline on 1800 123400 or Crime Stoppers on 1800 333000.