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National Terrorism Threat Advisory System

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The threat of terrorism in Australia is not new and remains enduring and multifaceted.  It is the reason why the Australian Government took the step of raising the terrorism threat level on 12 September 2014.  The factors that underpinned that decision persist and some have worsened. 

In the past, terrorists had demonstrated a trend towards a larger attack of greater sophistication and organisation.  Whilst recent events overseas demonstrate that an attack of this nature cannot be ruled out, currently the most likely source of threat is an attack by an individual, or small group of individuals without external direction, using weapons and tactics that are low-cost and relatively simple.

A 'terrorist act' is an act or threat, intended to advance a political, ideological or religious cause by coercing or intimidating an Australian or foreign government or the public, by causing serious harm to people or property, creating a serious risk of health and safety to the public, disrupting trade, critical infrastructure or electronic systems.

Terrorist acts can involve:

  • Arson;
  • Bomb threat / hoax or an actual bombing;
  • Chemical, biological or radiological incident;
  • Hostage taking / kidnapping;
  • Assassination;
  • Sabotage;
  • Product tampering; and
  • Cyber terrorism.

The new National Terrorism Threat Advisory System, announced on 26 November 2015, is a tiered structure with five levels of alert to indicate the National Terrorism Threat Level.  It informs Australians about the likelihood of an act of terrorism occurring in Australia and has been designed to provide as much information as possible to the public to allow them to make informed decisions and in broad terms, guide national preparation and planning.

The System helps to inform national preparedness and planning as well as indicate the appropriate level of precaution and vigilance to minimise the risk of a terrorist act. It is also used as the basis for public discussion of the risk of a terrorist act occurring in Australia.

The five levels of alert are:

  • Not Expected (green) 
  • Possible (blue)
  • Probable (yellow)
  • Expected (orange)
  • Certain (red)

The new National Terrorism Threat Advisory System applies across all States and Territories.  Information specific to the local security context is available from State and Territory police.

The community will be notified of any change to the threat level.

More information on the new National Terrorism Threat Advisory System and advice on the current level is available at


Acknowledgement of Country

The Government of Western Australia acknowledges the traditional custodians throughout Western Australia and their continuing connection to the land, waters and community. We pay our respects to all members of the Aboriginal communities and their cultures; and to Elders both past and present.