Two children have died and five more have been injured in a horror rollover on the way home from school in Victoria.

It’s understood a 34-year-old woman was driving and there were seven children in the eight-seater 4WD in what may have been a car-pooling arrangement.

The vehicle reportedly ran off the road at Parwan, about one hour west of Melbourne, on Tuesday afternoon and rolled several times.

There were chaotic and distressing scenes as families rushed to the accident site and witnesses stopped to help.

One child, aged seven, died at the scene despite receiving CPR. A second child, an 11-year-old boy, died after being flown to hospital.

Five other children had minor injuries and the female driver was under observation in hospital.

Emergency services were called to the site of the single-vehicle crash shortly before 4pm on Tuesday.

Investigations into the circumstances surrounding the crash are ongoing.

“The vehicle inexplicably rolled, we don’t know why,” Victoria Police’s Tony Gentile said at the scene.

“This is just a really sad set of circumstances.”

Channel Seven’s Sunrise reports the road had fairly recent sealing and potholes are not believed to have contributed to the accident.

Specialist ambulance resources remained at the scene of the crash, near the Nerowie and Parwan-Exford roads intersection, into Tuesday night.

They included two helicopter crews, mobile intensive care ambulance paramedic crews and five advanced life support paramedic crews.

“Their priority is with their patients,” an Ambulance Victoria spokesperson said.

-with AAP