Two young children were among seven people hurt after a speeding car being pursued by police ploughed head-on into another vehicle near Gisborne.
The crash happened on State Highway 2 near Te Karaka yesterday morning.
It was one of four separate crashes around the country yesterday that left two people dead and 15 others injured.
Police revealed last night that the Te Karaka crash happened moments after one of the vehicles was clocked speeding, and a police patrol car concerned about the vehicle briefly pursued the car. The police vehicle used flashing lights and its siren to signal to the driver.
"Within seconds of the officer initiating the pursuit, the vehicle has crashed into another vehicle further down the road," police said.
A 21-year-old woman was in a serious condition in Gisborne Hospital last night and a 4-year-old boy who was in the same car was stable. A 21-year-old man and 26-year-old man who were in the same vehicle were also stable.
A 38-year-old man, 18-year-old woman and 7-year-old girl travelling in the oncoming vehicle were all in a stable condition.
Three ambulances and a rescue helicopter attended the accident and the road was closed for several hours as the scene was cleared.
Police advised the Independent Police Conduct Authority about the incident.
The holiday road toll stood at three last night, barely a full day into the long weekend.
Last evening a 21-year-old man on a longboard - a longer version of a skateboard - died when he was hit by a car on the Kapiti Coast. He was boarding a long, winding road when he was hit.
In another fatal accident, the sole occupant of a vehicle died in Methven, near Christchurch, yesterday morning. The vehicle left the road and crashed into a tree in a rest area on State Highway 77.
Police were trying to establish the cause of the crash and the identity of the driver yesterday.
In another fatal accident, a woman aged 60 died when a van carrying seven tourists crashed on the Luggate-Cromwell Rd in Central Otago just after midday.
The van ended up down a bank after leaving the highway just past a tight corner at Queensberry.
Three ambulances, a rapid response vehicle and two rescue choppers were sent to the accident site and transported the remaining passengers to hospital.
Emergency services worked to free two of those injured from the van, though the remaining occupants were able to remove themselves.
Senior Sergeant Brian Benn said a serious crash investigation into the cause of the crash would be undertaken. The road was closed for several hours as the scene was cleared and police began their investigations.
In another incident, a 45-year-old female driver failed to take a corner and hit three pedestrians in the Christchurch suburb of Redcliffs yesterday afternoon.
Canterbury District Command Centre's Senior Sergeant Kath Pomfrett said the woman was arrested for driving while under the influence of alcohol.
One of the pedestrians was taken to hospital with serious injuries and the other two were treated at the scene.