The girls, aged one and three years old, had been listed in critical conditions with head injuries after being flown to the Royal Children’s Hospital after the accident happened just before 8pm Friday.

A hospital spokeswoman said one of the girls was more stable than the other.

Saturday: A Melbourne family had a traumatic start to the lead up to Christmas after their vehicle rolled over on Hamilton Highway near Hexham, leaving two young children with head injuries.

The two young girls, aged one and three, were airlifted to the Royal Children’s Hospital in Melbourne in a critical condition.

Sergeant James Van Engelen of Warrnambool police said the girls were aged one and three.

An Ambulance Victoria spokesman said a woman also suffered chest injuries in the accident and was taken to Geelong hospital in a serious but stable condition.

Sergeant Van Engelen said a man and two other children from the same family were taken to Warrnambool hospital with minor injuries for assessment.

The man was aged in his thirties and the two other children were of primary school age, Ambulance Victoria said. 

Sergeant Van Engelen said the accident happened just before 8pm on Friday night when the family was travelling west on the Hamilton Highway near Hexham.

It appeared the vehicle left the road and then over-corrected, with the rear end swinging sideways, he said.

The vehicle spun to the other side of the road and struck a power pole and flipped on to its roof, Sergeant Van Engelen said.

Eight ambulance units, including the Warrnambool air ambulance and another air ambulance based elsewhere, attended the crash.

The Hamilton Highway was closed for some time while emergency services attended to the injured.