Police are calling it "absolutely gutting" after five people have been killed in accidents overnight.
Three people died after a two-vehicle crash on State Highway 1, Waiouru, overnight, while one person remains missing.
Emergency services were called to the scene about 2.55am.
Three people were found dead at the scene, police said. Two further occupants sustained serious injuries.
Another person, who police believe was also in one of the vehicles, has not been accounted for. A search and rescue operation is underway to locate them.
Poice Superintendent Steve Greally, director of road policing, said a total of five people have died in crashes overnight.
One person has died following a crash in Wairakei, north of Taupō.
Another person died in a single-vehicle crash in Waiheke Island overnight. Emergency services were called to Onetangi Road around 1.30am.
"That is absolutely gutting," Greally said of the road toll .
"We are thinking of their families today, while they deal with the awful reality that their lives will never be the same."
There were two earlier deaths over King's Birthday weekend, bringing the provisional number of deaths to seven.
"We say it all the time but we're going to say it again - there are four main things that contribute to death or serious injury on the roads," Greally said.
"Those are speeding, not using your seatbelt, driving distracted, or driving impaired, including by tiredness.
"If you're getting on the road today, please - buckle up, put your phone away, watch your speed, and if you are at all impaired by alcohol, drugs or tiredness, stop - don't get behind the wheel.
"These things might be the difference between you getting home safely or not."
The Desert Road has reopened, but police are still working in the area and ask drivers to be cautious.
