Emergency services are at the scene of a crash that has blocked State Highway 1 at Domett in North Canterbury this morning.

The single-vehicle crash was reported about 10am and happened between Darrochs Road and Ethelton Road.

One person is reported to have critical injuries and will be flown to hospital.

The Serious Crash Unit has been notified and diversions are being put in place.

In a statement to Chris Lynch Media, a St John spokesperson said they were notified of a motor vehicle incident on Domett Road, Domett, at 09:56 today.

“One first response unit, one PRIME responder, one ambulance, one operations manager, and one helicopter attended, they said.”

North-bound traffic is being diverted along State Highway 7, From Waipara, while south-bound traffic is being diverted along Leader Road East at Parnassus.

Motorists should expect delays while the scene is cleared.

Road users should follow the directions of emergency services and expect delays. Detours will be available for light vehicles via State Highway 7, Route 70/Inland Road and Leader Road East/West.

Given it is a serious crash, people should be prepared for a closure of several hours.