Six people are injured after a two car crash in the Waikato.

The vehicles collided just before 12.40pm today on State Highway 31, Tihiroa, north of Otorohanga.

Northern fire communications shift manager Carren Larking said initial reports were that occupants were trapped, but this did not appear to be the case when the fire service arrived.

One person was airlifted to Waikato Hospital in a serious to critical condition, while five others were transferred to Waikato Hospital.