'Deliberate' Melbourne incident injures 19

CAR HITS PEDESTRIANS IN MELBOURNE CBD: WHAT WE KNOW:

* 19 injured, four critically.

* 32-year-old driver has a history of drug use and mental health issues and is in custody in hospital

* Another man, 24, was arrested but police believe he had no links to the incident

* There is no evidence linking the incident to terrorism

* Police believe it was a deliberate act

* White Suzuki Vitara crashed through pedestrians about 4.45pm Thursday, while up to 60 people crossed Flinders Street at Elizabeth Street

* Police said the driver accelerated as he drove on tram tracks down Flinders Street. One witness said he was travelling at up to 100 km/h

* The car crashed into a tram stop and stopped at the intersection of Flinders Street and Elizabeth Street

* The driver was arrested at the scene by an off duty police officer

* Pre-school child with a serious head injury among those hospitalised.