A six-year-old girl has sustained critical injuries, while three other children and two adults were also hurt following a horror collision at an arterial intersection in Adelaide's northern suburbs.

Emergency services rushed to the north Adelaide suburb of Virginia at about 11am on Sunday after receiving numerous reports of a major crash between a Toyota van and Toyota ute at the busy intersection of King and Penfield roads.

South Australia police said that six people were injured as a result of the crash, four of them children.

A 42-year-old Murray Bridge woman, who was driving the van at the time, and two children aged 11 and 10 who were passengers received minor injures and were taken to hospital.

The third child passenger in the van, a six-year-old girl received serious injuries and was rushed to hospital in a critical condition.

The 37-year-old driver of the ute and his four-year-old passenger also sustained minor injuries and were swiftly rushed to hospital.

Major Crash investigators have since arrived at the scene and are currently investigating the horrific collision.

Motorists have been warned to expect protracted delays with authorities closing the arterial intersection in all directions.

Phillip Nicol, who lives right on the intersection said he did not witness the crash but "flew out there" after hearing a loud bang.

Mr Nicol, who called an ambulance told the Adelaide Advertiser the two girls who were in the van at the time were injured "pretty bad."

He said the busy intersection had a long history of fatalities, and that an island needed to be erected.

Police are urging anyone who witnessed the crash or has relevant dashcam footage that may assist the investigation to contact Crime Stoppers on 1800 333 000.