The driver of one of the cars involved in a crash on State Highway 1 near Paekakariki this morning has been airlifted to Wellington Hospital with critical injuries.

The driver of the second car has been transported to Wellington Hospital by ambulance, with minor injuries.

Two passengers from the second car did not require medical treatment.

Two car collided head on on SH1 just south of Paekakariki at about 11.30am, closing the highway between the railway overbridge and Pakakariki Hill Road.

Diversions are in place via Paekakariki Hill Road for southbound traffic and Ames Street, Paekakariki for northbound traffic.