State Highway 1 is likely to remain closed for several hours following a serious crash at Kawakawa.
Initial reports are that two northbound motorcycles collided with a southbound car on the middle bridge of the Three Bridges.
One motorcyclist is in a critical condition, the other is in a serious condition.
The crash occurred just before midday. The injured motorcyclists have been flown to hospital by the Northland Rescue Helicopter.
Road closures are in place at Pakaraka and Kawakawa. Motorists are being diverted through Paihia via State Highways 10 and 11.
Police expect the diversions to cause delays and result in congestion on the alternative route.
"Motorists are advised to delay travel where possible and to take extra care and be patient on the lengthy diversion."