Islamic State: Australian 17yo Abdullah Elmir's friends defend his decision to join jihadists

Friends of a Sydney teenager who has appeared in an Islamic State (IS) propaganda video have defended his decision to join the jihadist group.

In the video directed at Prime Minister Tony Abbott, which emerged on Tuesday, 17-year-old Abdullah Elmir said the terrorist group "will not stop fighting" until it controls "every single land".

The video has been condemned by Australian Muslim groups. Political leaders have described the footage as "chilling" and said it shows why the West must stop IS's advance across the Middle East.

The ABC can reveal Elmir was a student at Condell Park High School in Sydney's south-west and disappeared in June, along with another 16-year-old Australian boy.

It is believed the pair travelled to Turkey and then crossed the border into Syria to join IS militants, but the other boy has since returned home.

Before travelling to the Middle East, Elmir had a love of theatre and last year, while in year 10, wrote about looking forward to more great performances.

One of Elmir's friends told the ABC via social media that "his friends were taken by surprise by his sudden departure".

"It's causing a lot of conflict on social media," she said.

"His close friends are trying to get everyone to respect Abdullah's decision and not cuss him as he was just as normal as anyone else."

Another friend told the ABC through Facebook: "Never make judgements on a situation you've never been in. Never make judgements on decisions you've never had to make."

While another said: "I swear, people get mad because we defend his legacy, he is still our mate and that's not changing anything."

Young extremists motivated by social isolation: social worker

Muslim community leaders in Australia have condemned the video and are worried about Elmir's future.

Silma Ihram from the Australian Muslim Women's Association said she was saddened Elmir had been taken advantage of by Islamic extremists and warned more needed to be done to de-radicalise youths.

"I'm really terribly disappointed in seeing a young man destroy his life like that and upset and angry at the people who've duped him into thinking he'll be a hero by being part of their PR campaign," she said.

"We believe there could be a lot more investment in resources to support religious leaders, those who mentor young people to support families in intervention strategies."

Lydia Shelly, a solicitor with the Muslim Legal Network, said they are also trying to piece together what led the teenager from Bankstown to join the IS group.

"I'm very worried as well about this boy who has made such a silly, silly, absolute foolish decision to go over there," she said.

"I'm very saddened and a lot of other mothers in our community share that same view. The fear that's in your heart as a non-Muslim Australian is also in our hearts as well.

"We need to understand the issues of radicalisation and exactly what attracts those people, especially young men, to these organisations."

A community worker, who does not want to be identified, has run his own de-radicalisation workshops and said young Muslims are often motivated by social isolation.

"Some of the things that have come up, to be really honest with you, is a deep sense of concern about the injustices that are happening overseas and this need, or a perceived need, to want to do something about it," he said.

"And these overseas groups are an avenue to express that need in a very tangible way, albeit obviously wrong."

New laws needed to fight extremism: Frydenberg

The Prime Minister's Parliamentary Secretary Josh Frydenberg said Elmir's decision to join IS and the release of the video demonstrates why stronger counter-terrorism laws are necessary.

"It's a reminder of the threat we face by radicalised young people," he said.

"That is why the Government has acted swiftly but also thoughtfully and in a considered way to introduce new legislation and to resource our intelligence and law enforcement agencies better so that we can meet this challenge and protect the local community."

The Government hopes its proposed Foreign Fighters Bill will pass Parliament within a fortnight.

But Ms Shelly said in Elmir's case, the legislation would have made little difference.

"We're quite concerned about this, and we also need to look at how we're going to tackle this problem holistically," she said.

"At the moment, we've only got legislative approaches as a response on the table, particularly that Foreign Fighters Provision Bill, and I note that if that act was empowered now, it wouldn't have stopped this young boy from going over, and that concerns me."

The Opposition have signalled their support for the Government's proposed legislative changes, however, the Greens and Liberal Democrat Senator David Leyohjelm said the laws were not required.