The Serious Crash Unit is examining the scene and SH10 is closed with diversions in place.
The two injured people were taken to Bay of Islands Hospital.
Diversions are via SH10, Te Ahu Ahu Rd, Waimate North Rd, and Wiroa Rd, back to SH10.
The deaths bring the Easter weekend road toll to six, which is four more than the total for the holiday weekend last year.
Yesterday police named the two children who were killed in a crash on Desert Rd on Good Friday.
They were 4-year-old Arteen Mosaferi, and Radeen Mosaferi, who was 2 months old.
The boys were from Hamilton.
Arteen died at the scene and Radeen died at Starship Hospital yesterday from his injuries.
Another person involved in the crash remains in a critical condition in Waikato Hospital.
The Serious Crash Unit and the Commercial Vehicle Safety Team are investigating the crash, which involved two cars and two truck and trailer units.
Police were called to the crash, between Waipakihi Rd and Rangipo Intake Rd, about 3.30pm on Friday.
The boys were correctly restrained in car seats.
Another crash on Friday in Tirohanga, between Pokuru and Tirohanga Rds, north of Taupo, killed Taupo woman Denise Tito.
Tito was grieving the loss of her mother and will share a double funeral with her.
On Saturday morning, a person died after a motorbike and truck collided in Rotorua.
Horrified crash witnesses said the motorbike lost control and went under the truck's wheels.
The motorcyclist died at the scene despite frantic efforts from members of the public to resuscitate him.
The official Easter holiday period began at 4pm Thursday, March 29 and ends at 6am today.
