One person is seriously injured and another moderately injured after a two-car crash on State Highway 3 in the South Taranaki District.

The seriously injured person was taken to Taranaki Hospital by helicopter, while the moderately injured person was taken to the same hospital by ambulance at 5.55pm, a St John spokesman said.

Fire Emergency New Zealand crews were working to extracate one person at the crash site south of Waverley at 4.55pm.