On the morning of 18 September 2014, police in Australia carried out the biggest counter-terrorism operation in the nation's history, with over 800 heavily armed officers targeting households in the cities of Sydney and Brisbane. It came days after the Australian government raised the terror threat from medium to high due to concerns about Australian citizens returning to the country after fighting with the Islamic State of Iraq and the Levant (ISIL). Following the raids, two people were charged, one with terrorism offences and the other for possession of an unauthorised firearm. One of the two arrestees became one of only two men on remand at the highest security prison in Australia, as he is considered an "AA" security risk.