One person has died following a serious crash involving two vehicles on State Highway 1 near Waiomio Road, just south of Kawakawa in Northland.

A further two people were injured in the crash, one of whom is in a critical condition and has been flown via helicopter to Whangārei Hospital.

The other is in a moderate condition and has been driven to Bay of Islands Hospital.

At 7.30pm State Highway 1 remained closed just south of Kawakawa and diversions were in place while the Serious Crash Unit examined the scene, a police spokesperson said.

St John ambulance service confirmed they were called to the scene at 5.11pm and had sent three ambulances, a rapid response unit, a helicopter and a manager.