CCTV footage has emerged showing the moment three South Auckland schoolgirls crossed a busy road before being struck by a car.

The two five-year-olds and a 10-year-old were on their way to school when a car hit them near Otahuhu police station on Great South Road just before 9am, police say. The girls are now recovering in hospital.

The CCTV footage shows the girls preparing to cross Great South Road. They ran straight into the path of an oncoming vehicle.

Sergeant Matthew Child of Counties Manukau Police says initial indications from reports are that the vehicle was travelling at the speed limit or under, in the line of traffic going, through the green light.

He says the women driver had just dropped off her children at the primary school and was on her way home.

Police say the girls should have been accompanied by an adult crossing the busy road.