Police need to be vigilant to prevent so-called sleeper cells of young, radicalised Muslims carrying out attacks on Australian soil, Iraq's Ambassador to Australia has warned.
Dr Hussain Al-Ameri said groups of teenagers were being targeted by preachers of Wahhabi-Salafism Muslim ideology.
"These groups are killers," the ambassador told SBS News.
"They are killers, and they unfortunately abuse the name of Islam.
"The teenagers, the strong believers, the poor people who are in need of money. All these people are good targets for such ideology."
Dr Al-Ameri said Australian police needed to maintain constant vigilance in monitoring the groups.
"They must not sleep," he said.
"They must keep control, they must be always be aware."
Watch the Iraqi Ambassador speak on sleeper cells:
The warning comes on the same day that Fairfax Media the Turnbull government is considering a move to merge half-a-dozen federal agencies into one mega-department, in the style of the United States' Department of Homeland Security.
The rumoured merger, which has not been confirmed or denied by the government, would see the Australian Security Intelligence Organisation (ASIO) and the Australian Federal Police join with other agencies currently contained in the Department of Immigration and Border Protection.
Prime Minister Malcolm Turnbull, who is in Indonesia on a state visit, would not comment on the report.
"I'm not going to comment on that sort of speculation about administrative arrangements," Mr Turnbull said, ending the press conference.
Watch the Iraqi Ambassador speak on Muslim extremism:
Under the reported proposal, ASIO would be removed from the Attorney-General's department.
Several government figures have joined the Prime Minister in describing the report as 'speculation'.
"I'm not going to delve into speculation," Environment and Energy Minister Josh Frydenberg said of the Fairfax report, which quoted unnamed sources.
But the departmental restructure has the support of Jim Molan, a former senior officer in the Australian Army who helped co-ordinate Coalition forces after the invasion of Iraq in 2003.
"It's a very, very good idea ... it's a very logical thing," Mr Molan said, arguing that the growing magnitude and sophistication of terror threats warranted a larger department.
"We should never take for granted that - although we're doing well now - we will always do well into the future."
The retired Army general was also a Liberal senate candidate in last year's federal election, though he failed to win a seat.
Former Prime Minister Tony Abbott appointed him a special envoy on the maritime asylum seeker prevention policy, Operation Sovereign Borders.
Mr Molan said Australia had done well to avoid the large-scale terror attacks seen in the US and Europe, but warned against complacency.
"We've got a choice," he said.
"We can either plan this well, implement it well, execute it well, with the smart people that we've got to do it, or we can wait until we have the equivalent of our 9/11 as the Americans did."
The United States merged 22 agencies to create its Department of Homeland Security in the wake of the September 11 terror attacks in 2001.
The objective was to improve the sharing of intelligence between all the different agencies.
But Labor MP and counter-terrorism expert Anne Aly told SBS News she questioned whether there was any real problem with how Australia's agencies share their intelligence right now.
She cited the creation of the Office of the Counter Terrorism Co-ordinator - an office designed to oversee data and intelligence sharing between agencies that was set up under the Abbott government, following a report that dismissed the need for a Homeland-style mega-department.
"A new big agency, similar to a Department of Homeland Security, would likely be less responsive and less agile because big departments tend to [mean] more bureaucracy," Dr Aly said.
Dr Aly was a university professor specialising in counter-terrorism before she entered parliament. In 2015, she helped advise the Obama administration on countering violent extremism.
She said a new security mega-department would likely be more secretive and less accountable.
"It certainly won't become more transparent," she said.
"That culture of opaqueness that we're currently seeing, that we currently have with Immigration and Border Control for example, as well as those other agencies that have a remit in the counter-terrorism space ... would be more concentrated."
It was the Abbott government's review of Australia's counter-terrorism machinery led to the establishment of the Office of the Counter Terrorism Co-ordinator.
The Turnbull government is now conducting its own review of the country's intelligence agencies.
Liberal senator Scott Ryan says the government will wait for that report to be handed down before it makes any changes.
"I'm not going to add to the speculation that's in this morning's press," he said.
"The prime minister has commissioned a review. That review will come forward when it's complete."
