Two children and an adult have been killed after a car smashed into a tree near Whangārei early yesterday morning.
Emergency services, including fire crews and ambulance, were called to the scene on Whananaki North Rd at 2.15am yesterday.
Police said a 12-year-old, a five-year-old and an adult were killed in the crash, while another child was critically injured.
A fifth occupant of the vehicle received minor injuries.
The road was closed overnight while police conducted a scene examination and an investigation is under way to establish the circumstances of the collision.
The crash came after Northland police posted on their Facebook page on Saturday warning of a high crash risk.
"Take extra care on Northland roads today. After a long dry spell there may be oil, fuel and other contaminates on the road surfaces. These will become slippery when mixed with water," the post said.
It was a horror weekend on North Island roads as four people were killed in three separate crashes in Waikato.
Two people lost their lives in a crash in Leamington, south of Cambridge, about 6pm on Saturday; One person died in a two-vehicle crash in Tahuna, 18km north of Morrinsville, about 10.30am Saturday; and on Saturday night a fourth person died when their vehicle crashed into a power pole on State Highway 25 near Pipiroa, 15km southwest of Thames.
Police acting national manager of road policing Inspector Gini Welch said while it is too early to say the causes of these collisions, most deaths that happen on the roads are avoidable.
"Every loss of life on our roads is a tragedy and these deaths will have a major impact both on individual families and wider communities."
NZ Transport Agency road safety senior manager Fabian Marsh urged drivers to remember the basics when it comes to safe driving including wearing a seatbelt, avoiding distractions, driving within the speed limit and never getting behind the wheel intoxicated.
"All of us can make mistakes when we're driving, and we are all vulnerable in a crash. But we can all take a few simple steps to make sure a mistake doesn't result in loss of life or limb.
"Mistakes are inevitable, but deaths and serious injuries from crashes are not."