A 12-year-old boy has died days after a horror collision involving five cars on the Monash Freeway in Melbourne.

The boy was rushed to the Royal Children’s Hospital in a critical condition with upper body injuries after the crash near the Stud Road off-ramp around 2pm on Sunday.

Police have today confirmed that he died from his injuries yesterday.

The cars collided near the Stud Road off ramp just after 2pm police said.The cars collided near the Stud Road off ramp just after 2pm police said. (Nine)

A 46-year-old Sunbury woman who was in the same Mazda as the boy was also critically injured in the crash and was taken to the Alfred Hospital for treatment.

An eight-year-old girl also in the car was hospitalised with minor injuries.

The three occupants of a blue Mitsubishi – a 68-year-old Campbellfield woman, a 39-year-old Glenroy woman and a six-year-old girl – were taken to hospital with non-life-threatening injuries.

Two people are in a critical condition after a five-car collision on the Monash Freeway in Melbourne.Two people are in a critical condition after a five-car collision on the Monash Freeway in Melbourne. (Nine)

Those in the three other vehicles involved in the crash were not injured.

The driver of a Volkswagen Tiguan, a 34-year-old Berwick man, was arrested and released pending inquiries.

Major Collision Investigation Unit detectives are continuing to investigate the circumstances of the crash.