Details are emerging about the life of young terror suspect Numan Haider, who was shot dead outside a Melbourne police station after stabbing two officers.

Counter-terrorism officers wanted to chat to Numan Haider after becoming concerned about the 18-year-old’s behaviour and escalating rhetoric.

The terror suspect’s passport was cancelled a week ago on national security grounds but police say they weren’t about to arrest him when he turned up for a pre-arranged meeting at a Melbourne police station.

Within moments of shaking his hand, the two police officers were stabbed and Mr Haider was shot dead. A second knife was found on his body.

“His actions may tell a story of what his intentions were,” Victoria Police chief commissioner Ken Lay said on Wednesday.

There were also unconfirmed reports he had a black flag linked to jihadist group Islamic State, or ISIL.

The Narre Warren man had been on the police radar for three months, but authorities say he was acting alone when he violently lashed out at the police.

“This is an incident resulting from the actions of one individual,” Victorian Premier Denis Napthine said.

“It is not about faith, it’s not about ethnicity, it’s about the alleged behaviour of an individual.”

Fairfax Media reported Mr Haider may have planned to behead the officers, after ISIL on Monday issued a statement asking its followers to directly target Australians and citizens of other western countries. Police declined to comment.

The incident comes a week after Australia’s biggest counter-terrorism raid, involving hundreds of officers, unearthed allegations of an IS-driven plot to abduct a member of the public and film him being beheaded.

Officers had become concerned Mr Haider’s behaviour had escalated in the past week, and he had been seen in a shopping centre displaying an IS flag, Mr Lay said.

“We learned of some behaviours that were causing us significant concern and our interest was greatly heightened,” he said.

But Mr Lay said the joint counter terrorism taskforce officers did not intend to arrest Mr Haider.

“We were just needing to have a chat and we just wanted to test some of his thinking,” he said.

Mr Haider came willingly to the Endeavour Hills police station on Tuesday night, but wanted to meet the police in an adjacent car park.

After shaking hands, Mr Haider repeatedly knifed the Australian Federal Police officer in the stomach, head and neck and the Victoria Police leading senior constable was stabbed twice to the forearm, police said.

The Victorian policeman then fired a single shot, killing Mr Haider on the spot.

Mr Haider’s family had tried to prevent him from leaving their house on Tuesday and were concerned for his safety, the ABC reported.

But contrary to some reports, AFP acting commissioner Andrew Colvin said Mr Haider hadn’t made any “specific” threats against Prime Minister Tony Abbott.

The Islamic Council of Victoria (ICV) has already received a number of threats since Tuesday’s incident.

“Threats, language against the family of the young man, clearly there are – and I use this deliberately – extremists on all sides of the community,” ICV secretary Ghaith Krayem said.

Mr Krayem said the black flag being used by IS has a deep historical significance for Muslims and had been co-opted by the group.

“Right now that flag poses a real point of sensitivity, and somebody who was thoughtful and mature would not be going around waving the flag,” Mr Krayem said.

Mr Krayem said he would wait for investigations to conclude before judging Mr Haider’s actions.

“I’m not going to condemn what he did because we don’t know what he did,” he said.

Mr Abbott, who has travelled to the US for international meetings on the response to IS, said the incident underscored the need for police and community vigilance.

“Obviously, this indicates that there are people in our community who are capable of very extreme acts,” he said.