Timeline: Australia' s counter terrorism efforts
21 Jul: Officials say Australian suicide bomber behind Iraq blast; concern grows over the number of Australians fighting for Islamist militant groups in the Middle East and the effect of them and their supporters and sympathisers on domestic security.
5 Aug: New legislation aimed at preventing people going to fight with Islamist groups announced.
11 Aug: Image emerges of young son of Australian militant fighter holding severed head of Syrian soldier.
27 Aug: New counter-terrorism units set up in airports to stop departing fighters.
27 Aug: Director general of Australia's spy agency, David Irvine, says 15 Australian militants have died fighting in Iraq and Syria. One hundred or more people in Australia are "actively supporting" militant groups by recruiting new fighters and providing funds, he says.
10 Sep: Brisbane Islamic centre raided; two charged with terrorism offences.
12 Sep: Australia raises terror threat level from medium to high, for the first time since the system was introduced in 2003.
14 Sep: Prime Minister Tony Abbott commits 600 troops to fight against Islamic State, as part of a multilateral effort.
18 Sep: Australia carries out what it calls its biggest counter-terrorism raid; Mr Abbott later confirms this was linked to an alleged plot by Australia-based individuals to kill a randomly selected member of the public. The intelligence is reported to have come from an intercepted telephone call involving an Australian fighter with Islamic State (IS) in Syria.
23 Sep: A teenager described as a "known terror suspect" is shot dead after he stabs two police officers at a Melbourne police station.
3 Oct: Australia approves air strikes against IS.
8 Oct: Mr Abbott proposes ban on foreign "hate preachers".
29 Oct: The government says it is trying to confirm reports that the most senior Australian member of IS, Mohammad Ali Baryalei, has been killed in Syria. The news comes on the same day that the senate passes the foreign fighters bill.
4 Dec: Australia bans its citizens from travelling to the Syrian province of Raqqa, stronghold of IS.
15 Dec: At least one gunman takes hostages in a cafe in Sydney's Martin Place.
(Source: BBC)