Four injured in car collision north of Auckland

Emergency service workers are trying to free those inside the vehicles. File photo

Four people were injured - one seriously - when two cars collided north of Auckland today.

There is a large traffic backlog as emergency services work to clear the road after the crash in Warkworth that happened about 12.10pm.

Police Northern Communications Shift Inspector Chris Tate said the crash happened on State Highway One between Woodcocks Rd and McKinney Rd.

He said three people suffered moderate injuries and one person was taken to hospital in a serious condition.

Serious crash were investigating and the arterial route was completely closed.

Diversions are in place and police hoped to open the road by 3.30pm.

The Fire Service and Westpac Rescue Helicopter also attended the scene.