A terror suspect shot dead after he stabbed two Australian counterterrorism police officers had his passport canceled on national security grounds and had recently displayed what appeared to be a flag of the Islamic State group, top police officials said Wednesday.

Some experts suspect Tuesday's attack was inspired by the Islamic State group's call to supporters to wage terrorism in their home countries.

An Australian Federal Police officer and a Victoria state police officer who were part of a counterterrorism team had asked the 18-year-old to come to a police station in Melbourne to answer questions after first drawing their attention three months ago, Victoria Police Chief Commissioner Ken Lay said.

The trio shook hands before the man began stabbing the officers, Australian Federal Police Commander Bruce Giles said. One of the officers then shot the man dead.

The officer had no choice but to shoot, said Victoria Police Assistant Commissioner Luke Cornelius.

Police haven't released the suspect's name, but opposition leader Bill Shorten identified him in Parliament as Numan Haider.

A second knife was found on the man after he was shot, Lay said. Both officers were in stable condition Wednesday.

The man had recently exhibited behaviors that had caused police "significant concern," Lay said, including being seen waving what appeared to be an Islamic State flag at a shopping center.

Australian Federal Police Acting Commissioner Andrew Colvin said the man's passport was canceled about a week ago on national security grounds.

Brett Zarb, spokesman for GPT Group that owns the Dandenong Plaza shopping center, said police had asked the mall for security footage of Haider's brief visit to the complex last Thursday.

Zarb said Haider had been accused of displaying the Islamic State flag at around 4 p.m. that day. He did not create any disturbance, he said.

Asked about reports that the man had also threatened Prime Minister Tony Abbott, Colvin said the man had not made any "specific threats."

Abbott is en route to New York to attend a United Nations Security Council meeting on the 15,000 foreign fighters who are in Iraq and Syria.

"Obviously this indicates that there are people in our community who are capable of very extreme acts," Abbott said in a video message from Hawaii.

A statement issued by Islamic State group spokesman Abu Muhammad al-Adnani and made public this week asked Muslims to use all means to kill a "disbelieving American or European — especially the spiteful and filthy French — or an Australian or a Canadian" or others whose countries are trying to disable the group.

Australian National University Professor of National Security Michael Wesley blamed the statement for the attack.

"I think that this attack occurring in the context of the fatwa that came out earlier this week, a fatwa that implored followers to attack infidels and ask no one's permission, thereby really an incitement to lone-wolf attacks — I don't think that's a coincidence at all," Wesley said.

Yahya Safi, member of the Australian National Imams Council, called for calm.

"The recent so-called fatwa from overseas making reference to Australia as a target has no religious authority and must be rejected," he said.

Islamic Council of Victoria Secretary Ghaith Krayem said his group had on Wednesday received threats against Muslims and the man's family. He urged people not to jump to conclusions about the man's motivations, saying that many 18-year-olds rebel against authorities without being terrorists.

The Defense Department announced Wednesday that an Australian air force contingent had arrived in the United Arab Emirates. The jets are expected to be used in airstrikes against Islamic State fighters in Iraq, although Australia has yet to commit to a combat role.

Earlier this month, Australia raised its terror warning to the second-highest level, citing the domestic threat posed by supporters of the Islamic State group. Last week, police detained 16 people in counterterrorism raids in Sydney and charged one with conspiring with an Islamic State leader in Syria to behead a random person.

On Wednesday, the government proposed a law to making it an offense to simply visit terrorism hot spots abroad.


Associated Press writer Kristen Gelineau in Sydney contributed to this report.