Police said the 44-year-old from Essendon was stabbed in the chest and neck outside Moonee Ponds Central shopping centre about 4.30pm today when an argument between two men believed to be strangers quickly escalated.

Acting inspector Raj Tillekeratne said the victim, passersby and security from the inner-north-west shopping centre detained the alleged attacker before police arrived.

The 55-year-old from Fitzroy with what police described as “significant” mental health history was tonight in police custody awaiting a medical assessment before he could be interviewed.

Tillekeratne confirmed the man was heard saying “allahu akhbar” – Arabic for “God is great” – after he was detained. 

The inspector said the counterterrorism command had been contacted and police had “nothing to indicate that this is either religiously or politically motivated” so were treating it as “random, isolated offending”.

Tillekeratne described the victim, who was tonight in a stable condition in Royal Melbourne Hospital, as “very brave” and “quite lucky”.

“There could have easily been worse than what really occurred,” he said.

“So it’s pretty, he’s pretty lucky, I’d say.”

Police will increase patrols in the area.

No charges have been laid.