Nearly 900 police were involved in raids in Brisbane and Sydney aimed at foiling an alleged imminent terrorist attack, with 15 people arrested.

One was subsequently charged with conspiracy to carry out a terrorist attack, while another man was charged with possessing a prohibited weapon and ammunition.

Police allege the most senior Australian member of Islamic State, Mohammad Ali Baryalei, urged an Australian group to carry out a series of violent acts in Brisbane and Sydney.

The plan was to snatch people off the street, drape them in an Islamic State flag and behead them.

Please scroll back through our blog to see how the day's events unfolded.