The Australian Jewish News is reporting that one of the victims was a 10-year-old girl from Beth Rivkah College in St Kilda East. The publication also said the girl's mother and sister were in hospital in a critical condition.

A three-month-old baby girl who was rushed to hospital by police officers is among six people with life-threatening injuries.

Three people are in a critical condition at the Royal Melbourne Hospital and two are in a critical condition at The Alfred. (One of these people may since have died)

An additional 23 people are being treated for injuries in Melbourne hospitals, including some who went into shock after witnessing the incident.

Mr Gargasoulas, 26, has been arrested. He is in hospital after being shot in the arm by police.

Mr Gargasoulas is accused of stabbing his brother, Angelo, in his mother's public housing flat in Windsor on Friday morning. Police said he has a history of family violence, as well as mental health and drug problems.

On Wednesday night, Mr Gargasoulas allegedly attacked 76-year-old Gavin Wilson, who lives at his mother's housing commission flats, and demanded the keys to his car.

The car, a maroon sedan, was used in Friday's rampage.

Mr Gargasoulas, who is a father to a number of children, has been posting ranting and and angry comments on social media this week about God, war and police.

Police said the incident was not terror-related.