Police in the Australian city of Melbourne continue to question five suspects arrested in counter-terrorism raids.
All five are in their late teens and one has already been officially charged with conspiring to commit a terrorist act.
The 18-year-old, named as Sevdet Besim, was remanded in custody after appearing in court.
Australian Prime Minister Tony Abbott gave more details about the case at a media conference.
“The act that we believe was in preparation involved attacks against police officers on ANZAC (Australian and New Zealand Army Corps) Day (25 April).
“That’s as much as we can say at this stage except for this: that we believe that the attack was inspired by – or the potential attack was inspired by – the Daesh death cult in the Middle East.”
Daesh is the Arabic acronym for ISIL, or the group calling itself Islamic State.
Abbott is calling for people not to be put off attending ANZAC Day celebrations.
“The best thing you can do in the face of those who woul
