A serious two-vehicle crash has closed State Highway 1 in North Canterbury.

The crash happened on Parnassus Road (SH1) near McPhersons Stream Bridge, between Spotswood and Cheviot in the Hurunui District.

A police spokesperson told ChrisLynchmedia.com officers were called about 8.30am.

A St John spokesperson said two air ambulance helicopters, one prime unit, two operations managers, one first response unit and one ambulance responded to the scene.

The road was closed.

One person was removed from a burning truck and was in a critical condition.

Motorists are being asked to avoid the area.

A spokesperson for NZTA said people should delay travel and prepare for a closure that could last hours.