A police manhunt is underway after a car veered onto the wrong side of the road, colliding with three cars in Cranbourne on Thursday 13 December.
The drivers of two cars, a 19-year-old woman and a 31-year-old woman have also been taken to hospital with non-life threatening head injuries.
It is believed a vehicle travelling along South Gippsland Highway near Thompsons Road crossed over the median strip onto the wrong side of the road and collided with three cars about 12.30pm.
The driver and passenger of the first vehicle are perceived to be of Pacific Islander descent and were wearing dark hoodies.
Investigators believe the men were picked up by another vehicle, a blue sedan and left the scene driving south on the footpath.
Casey Highway Patrol officers are appealing for witnesses.
Anyone with information or who may have dash cam footage are urged to contact Crime Stoppers on 1800 333 000.