Australian authorities are investigating claims by Islamic State that an Australian teenage recruit died after blowing himself up in Iraq, and local media reported that bomb-making materials had been found at his family home in Melbourne.
A blog post believed to be written by 18-year-old Jake Bilardi, written under his pseudonym Abu Abdullah al-Australi, revealed how he had considered carrying out attacks on home soil.
Foreign Minister Julie Bishop told reporters on Thursday that security agencies were trying to verify reports that Bilardi had carried out a suicide attack in the Iraqi city of Ramadi.
Islamic State released an image on Wednesday claiming to show him getting ready to carry out the attack, as well as images of what appeared to be an explosion.
Iraqi officials said 13 vehicles attacked army positions in Ramadi, the capital of Anbar province. No details on casualties were given.
The Australian Broadcasting Corporation reported on Thursday that Bilardi had left materials for improvised explosive devices at his family home before going to Syria.
Bishop said she did not want to comment on whether Bilardi was involved in planning an attack in Australia.
"These are matters we are currently seeking to confirm, and once I've had a briefing from our agencies on these issues, I will make a comment on it," she told reporters.
In a blog post purportedly written from Anbar in January, Bilardi said he tried to make contact with Islamic State but fearing possible attempts by the "increasingly-intrusive" Australian authorities to prevent his exit he drew up a "Plan B".
"This plan involved launching a string of bombings across Melbourne, targeting foreign consulates and political/military targets as well as grenade and knife attacks on shopping centers and cafes and culminating with myself detonating a belt of explosives amongst the kuffar," the blog read, using a derogatory term for non-Muslims.
He gave up the plan, fearing it would be thwarted by the police, according to the blog.
Australian Federal Police said they were aware of the blog but declined to comment on its authenticity.
Australian security forces believe 90 citizens are fighting alongside Islamic State, and 20 Australians are understood to have died.
Australia is on high alert for attacks by radicalized Muslims or home-grown militants returning from fighting in the Middle East. In December, two hostages and a radical self-styled sheikh who had sought to align himself with Islamic State were killed in a Sydney hostage siege.
