“We believe that this person was there with those sorts of intentions, albeit we don’t know whether it was something planned at this stage,” Chief Commissioner Graham Ashton told Seven on Tuesday morning.
“… We are treating it as a terror attack.”
Islamic State has claimed responsibility for Monday’s incident, that left an employee of the Brighton serviced apartments where the siege occurred dead.
Police have confirmed the gunman was Yacqub Khayre, who was killed in a shootout with police.
“The attack in Melbourne, Australia was carried out by a soldier of the Islamic State in response to the call for targeting the subjects of the coalition states,” the group’s Amaq news agency said.
IS blamed the attack on Australia’s membership in the US-led coalition against the militant group.
Ashton said Khayre had been linked to the Holsworthy army barracks terror plot in 2009.
He had taken a prostitute hostage and forced her to ring the Seven Network’s Melbourne newsroom on Monday afternoon.
She said she was in a hostage situation before man came on the line saying “This is for IS, this is for al-Qaeda”.
Ashton earlier told Nine that the gunman had been known to police because of his background “in relation to terrorism matters, albeit some years ago.”
He said there had been no information that he had been planning an attack.
“He is someone certainly known to us from his background but certainly as of yesterday there wasn’t anything that we had that suggested that he was planning on embarking on this, that this was anything more than a spontaneous act.”
Sources told the Herald Sun he was rated as “a low-risk person of interest” by anti-terror police.
Khayre was acquitted over the terror plot to launch a suicide attack against Sydney’s Holsworthy army barracks in 2009 after a trial in 2010.
In 2007, he was charged with armed robbery after holding up passengers on a Melbourne train, leaving one man with knife wounds.
Police were called to the Brighton serviced apartment building at 5.41pm on Monday to reports of an explosion.
When they arrived, they found a man apparently shot dead in the foyer.
They began efforts to negotiate with the gunman who was holding a woman hostage in one of the apartments.
Deputy Commissioner Andrew Crisp said on Monday night that the man spoken to by negotiators inside the building came out about 6pm and opened fire, hitting three police.
They returned fire and killed him.
Two male officers were taken to hospital for treatment while another was treated at the scene.
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