Melbourne car attack: what we know

WHAT HAPPENED?

* A 32-year-old man drove a white 4WD on tram tracks on Thursday to deliberately hit 18 pedestrians, leaving three critical and more than a dozen others injured

THE INJURED

* Twenty people were admitted to hospital, including the driver and an off duty policeman who arrested him

* Three are in a critically condition - an 83-year-old Northcote man and two South Korean men aged 67 and 61

* Nine foreign nationals among those injured

* Those in a stable condition are a 40-year-old Venezuelan man from Elwood, a Richmond woman aged 47, a 45-year-old Indian man, a 36-year-old Mentone woman, a 35-year-old Mernda woman, a 30-year-old Craigieburn woman, a 25-year-old Irish woman living in Caulfield, a 24-year-old Chinese man and a four-year-old South Korean boy

* A Seaford woman, 33, a 17-year-old Brunswick boy, a 25-year-old Italian man, and a 43-year-old New Zealand man living in Heathmont have all been discharged

* The off-duty policeman who arrested the driver has undergone surgery and is stable

* Two Melbourne woman aged 58 and 25 went to hospital, but were not admitted

THE DRIVER

* An Australian citizen who migrated from Afghanistan via a refugee program

* Has a history of serious mental illness and drug abuse and made "utterings" to police after the incident about dreams, voices and "perceived mistreatment of Muslims"

* He was discharged from hospital on Friday and will be interviewed by police

INVESTIGATION

* Police raided homes in West Heidelberg and Oak Park overnight

MOTIVATION

* Police say there are no known links to terrorism at this stage., and nothing to indicate the event was planned.

SOURCE: Victoria Police