Two cars have collided on State Highway 2 in Waihī leaving four people hurt including two with life-threatening injuries.

Emergency services including two helicopters and four ambulances attended the scene of the serious two-car crash near Ford Rd in Waihī, Hauraki, which was reported around 9.35pm yesterday.

St John said two people suffered critical injuries and were flown to Waikato Hospital, while two others suffered moderate to serious injuries and were taken to Tauranga Hospital.

The road was blocked overnight and diversions were in place on Ford Rd and Woodlands Rd. However the road is open this morning.