A child is dead and five other people have been seriously injured, including a second child, following a head-on smash in Victoria’s south-west.

Two cars collided while travelling on the Hamilton Highway in Stonehaven, about 10 kilometres west of Geelong, about 9pm on Wednesday.

Emergency crews declared a child in one car dead at the scene.

A second child in the same car initially suffered life-threatening upper body injuries but an Ambulance Victoria spokesperson said on Thursday morning the girl was now in a stable condition.

She was initially taken to hospital in Geelong, before being flown to Melbourne’s Royal Children’s Hospital.

A man and a woman from the same car were also rushed to Geelong Hospital.

The man suffered serious injuries while the woman, who is in her 30s and had lower body injuries, is in a stable condition.

Two men travelling in the other car were taken to Geelong Hospital. Both have serious injuries.

The adults involved in the crash were aged in their 20s and 30s, the ambulance spokesperson said.

Victoria Police’s major collision investigation unit is yet to determine what caused the crash and investigations are ongoing.

Police are urging anyone who witnessed the crash or has footage or information to contact Crime Stoppers.

The child is the second fatality on Victorian roads four days into 2024.

-with AAP