Three cyclists were among 12 people who died on the roads at the weekend, the worst weekend toll of the year.
In Waikato, two cyclists were hit by a car near Morrinsville.
A 71-year-old man died at the scene and a 46-year-old man died shortly after being taken to Waikato Hospital.
A group of 10 cyclists was on the Morrinsville to Walton Road about 9am on Sunday when they were struck by the vehicle.
Sergeant Graham McGurk says they had just come down a hill and so were reaching speeds of 50km/h to 60km/h.
He says a car travelling in the opposite direction came around the corner and appears to have lost control and collided with the group of cyclists.
The 23-year-old woman driver suffered moderate injuries and was taken to Waikato Hospital.
Mr McGurk says it is too early to say if charges will be laid.
Third cyclist dies
A third cyclist died when she was struck by a car on State Highway 3 near Feilding on Sunday.
Patricia Anne Veronica Fraser, 34, from Longburn near Palmerston North, was training with her best friend for an endurance race around Lake Taupo. Ms Fraser was married with four children between five and 13.
Cycling Advocates Network programme manager Patrick Morgan says eight cyclists have been killed on the roads this year.
The 12 road fatalities at the weekend are three times the average for weekends over the past year. Among those who died was a 42-year-old pregnant woman in a head-on collision near Palmerston North.
Four of the deaths occurred in Waikato, where road policing manager Leo Tooman says several of the crash sites are being checked. He says police are so busy with this task it will be some time before they can say for sure what caused the crashes.