A pair of Katikati boys are fighting for life in Waikato Hospital following the horrific three-car crash on the Kaimai Ranges that claimed a nine-year-old Katikati girl's life last night.

The two are among six people injured in the head-on crash that happened near the summit of the ranges at about 4.15pm, closing a section of State Highway 29 for five hours.

A Nissan van crashed head-on with a Subaru Legacy on SH29.

A nine-year-old girl, who was a rear seat passenger of a blue Subaru with four others from Katikati, died at the scene.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says a Nissan van travelling west towards Matamata crossed the centreline on a moderate left-hand bend colliding head-on with a Subaru Legacy.

A Honda Civic travelling behind the Subaru towards Tauranga then crashed into the other two.

Four others in the Subaru, all from Katikati, were taken by St John Ambulance to Waikato Hospital.

Waikato District Health Board communications manager Mary Anne Gill says the two boys, aged five and 12-years-old, remain in critical condition in the hospital's Intensive Care Unit today.

The two women, aged 20 and 34-years-old, are in serious but stable condition in the hospital's high dependency unit.

The driver and passenger of the Honda Civic sustained moderate injuries, and the driver and sole occupant of the Nissan van, a 56-year-old Mount Maunganui man, was taken to Tauranga Hospital in a serious condition.

Bay of Plenty District Health Board communications manager Diana Marriott says the 56-year-old man is in a serious but stable condition today; and a 79-year-old Tauranga woman is in a stable and comfortable condition.

Ian confirms a 57-year-old woman from the Honda received minor injuries and did not go to hospital.

Multiple emergency services, including 20 firefighters, St John Ambulances from Tauranga, Tokoroa, Matamata and Cambridge and police from Waikato and Bay of Plenty attended the scene.

The blue Subaru Legacy sedan sustained major damage in the crash while the Honda and Nissan ended up in the middle of the highway facing towards Tauranga.

A section of SH29 was closed from 4.30pm with traffic diversions in place at both the Tauranga and Matamata side of the Kaimai Ranges. It re-opened five hours later at 9.20pm.

Ian says the devastating crash serves as a timely reminder for all motorists heading into Queen's Birthday weekend.

'Whilst speed isn't considered to be a contributing factor, it's extremely important that all drivers take a high level of care because an emergency situation like this can present itself at any second on the road,” says Ian.

'It's certainly sad and not a good lead up to the holiday weekend. On that note, its important people drive to make it to Monday.”

Police Crash Analysts attended the scene last night and Ian says investigations are continuing today.

Police are also asking for any witnesses to the crash yet to be spoken to by police to contact Tauranga Police on 07 577 4300.