(CNN) Australian Foreign Minister Julie Bishop says the government is seeking to confirm reports that an Australian teenager has carried out a suicide attack on behalf of ISIS in Iraq.

"I can confirm that the Australian government is currently seeking to independently verify reports that 18-year-old Melbourne teenager Jake Bilardi has been killed in a suicide bombing attack in the Middle East," she told reporters.

"If these reports are confirmed, this is another tragic example of a young Australian being lured to a senseless and violent death by a brutal terrorist organization that is intent on imposing suffering and misery not only in Iraq and Syria but beyond."

On Wednesday, ISIS claimed that "Abu Abdullah al-Australi," along with four other foreign fighters, had been killed while carrying out suicide attacks during an offensive launched on the city of Ramadi in Iraq.

The claim, issued on a Twitter account associated with the Anbar provincial division of ISIS, was accompanied by a series of 20 images, including a photo of a young man who looked like Bilardi.

The image appeared to show Bilardi at the wheel of a car with the caption, "Abu Abdullah al-Australi (may Allah accept him), the attacker on the 8th Brigade."

The other attackers hailed from Belgium, Syria, Uzbekistan and the Caucasus, the Twitter account claimed.

Chemicals at home

Victoria police said Bilardi first came to their attention when his family reported him missing last year.

A search of his family's home in the Melbourne suburb of Craigieburn following his disappearance uncovered chemicals that could be used to make an explosive device, police said, although no actual bombs were found.

Bishop said Bilardi's passport had been canceled in October on the advice of Australian security agencies.

Australian media have reported that Bilardi kept a since-deleted blog, written under his alias Abu Abdullah al-Australi.

Entitled "From Melbourne to Ramadi: My Journey," it reportedly detailed his transition from an "atheist school student in affluent Melbourne to a soldier of the Khilafah preparing to sacrifice my life for Islam."

The blog reportedly described a plan to attack targets in Melbourne, after an initial attempt to move to Iraq or Syria failed.

"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 centres and cafes and culminating with myself detonating a belt of explosives amongst the kuffar," he wrote, according to the Sydney Morning Herald.

Loss of mother

Member of Bilardi's family have linked the teen's radicalization to the loss of his mother from cancer.

"He's just a young boy that went looking for something after he lost someone very very dear to him, his mother," his aunt, Connie Bilardi, told CNN affiliate Seven on Monday.

A former classmate of Bilardi's from Melbourne's Craigieburn Secondary College described the teen on Facebook as a "shy kid who didn't like to be disturbed".

"One day, he randomly got angry at me and tried to punch me," he posted.

"Always keep an eye out on the quiet ones."

Extremist Facebook posts

A former penpal of Bilardi told CNN he cut off communication with the teenager about two years ago, when Bilardi started posting Islamic extremist messages on his Facebook page.

The friend, who requested not to be named, said he first met Bilardi on the website interpals.net about seven years ago. They shared a love for soccer -- Bilardi was a supporter of Chelsea Football Club -- and became penpals.

Bilardi told him about his mother's death, and confided that he was fighting with his family, because they would not allow him to go overseas to study.

The penpal said he started noticing a change in Bilardi's behavior when the teen started posting "things that supported Osama bin Laden" on Facebook.

"I got scared," the friend said. "My friends here told me that maybe I should stop talking to him." He blocked Bilardi on the social networking site about two years ago.

After a while, he said, he got curious about how his old penpal was doing. "I thought he was my friend. I wanted to make sure he was okay... I sent him an email saying 'Are you well?' but he never wrote back."

Australians fighting for ISIS

Bishop said that 90 Australian citizens are in Iraq and Syria fighting on the side of ISIS, and that at least 20 Australians have been killed in the conflict.

The passports of some 100 Australians had been canceled on national security grounds, she said.

Bishop appealed to young Australians "not to fall victim to this brutal terrorist organization, to not be lured into believing that they're embarking on some adventure or some romantic endeavor."

"This is a brutal organization dedicated to creating misery and hardship," she said. "Its activities of beheadings and executions and crucifixions all take us back to the dark ages."

Australian Prime Minister Tony Abbott addressed Bilardi's alleged suicide attack in comments to the press Thursday.

This is a horrific situation -- an absolutely horrific situation -- and it shows the lure of this death cult to impressionable youngsters," he said. "It's very, very important that we do everything we can to try to safeguard our young people against the lure of this shocking alien and extreme ideology."