Motorists are being urged to avoid State Highway 10 near Kaingaroa, in the Far North, after a serious crash involving two trucks.

The collision occurred about 12.40pm at the intersection with Pukewhai Rd, roughly midway between Awanui and Taipā.

Both lanes are closed and diversions are being set up, most likely at Duncan Rd and Parapara Rd. Both roads, however, are narrow and unsealed.

Heavy traffic may be diverted via Oruru Rd and Fairburn Rd.

Police, Kaitaia and Mangōnui fire brigades, and St John Ambulance are at the scene.

At least one driver is understood to be in a critical condition.

A landing zone is being set up for the Northland Rescue Helicopter.

The police Serious Crash Unit and the Commercial Vehicle Investigation Unit have been notified and are believed to be en route.

One of the vehicles involved is believed to be a refrigerated truck.

More information to come.