One person has died and another four have been injured in a crash on State Highway 1 in the north of Auckland. 

The crash happened near Cowan Bay Rd in Warkworth. 

State Highway 1 is closed between Puhoi and Warkworth. 

St John attended the incident at 1.38pm. Initially four people suffered moderate injuries and one had critical or life-threatening injuries. 

Police later confirmed that the critically injured person had tragically died. One of the people listed initially as moderately injured was now in a serious condition. 

Five St John vehicles attended the crash and at least one is still there. A helicopter has also been dispatched. 

State Highway 1 is closed between Puhoi and Warkworth. Photo / via Google Maps 

"Please follow directions of emergency services. Delays in the area are likely," Waka Kotahi NZ Transport Agency tweeted. 

"Diversions may be required. Road closure is possible."