A nine-year-old girl has been killed and a six-year-old boy is in a critical condition, after a serious two-vehicle crash in central Queensland.

According to Queensland police, two vehicles collided at the intersection of Artillery and Yeppoon roads on Sunday morning.

The crash involved two families in separate hatchbacks — a 40-year-old Emu Park woman, with three children, aged six, nine and ten were in one car and a 33-year-old woman was with two girls aged eight and 12 in the other.

A child had to be cut free from one of the cars.

Two children, aged nine and six, from one of the vehicles were taken to Rockhampton Hospital in a critical condition but the nine-year-old girl could not be saved.

The boy was airlifted to Queensland Children's Hospital in Brisbane with life-threatening injuries.

Three other children and two adults were also taken to hospital with minor injuries and are in stable conditions.

Barry Thompson, from the Queensland Fire and Emergency Service, praised the actions of those near the crash.

"I've spoken to a number of the bystanders, and the actions they carried out before arrival of QAS and QFES personnel definitely assisted with the situation," Mr Thompson said.

"There was people in shock, varying degrees of injuries, it was definitely not a good incident.

"I think it's going to take a toll on my crews."

It is the fourth child to die in a traffic accident in a week, with two children killed in a single-vehicle crash at Peaks Crossing, and a three year-old killed in a service station carpark after being hit by a ute at Burpengary.