Emergency services are at the scene of a serious crash involving a vehicle and a pedestrian.

They were called to Riccarton Road, near Mona Vale Ave at 3.30PM.

A police spokesman told chrislynchmedia.com Riccarton Road is blocked off to motorists between Deans Avenue and Mona Vale Avenue and diversions are in place.

The Serious Crash Unit is at the scene and police are making further enquiries to determine the circumstances of the crash.

The road is expected to be closed for a few hours.

“Christchurch Police would like to acknowledge the members of the public who provided assistance at the time of the collision” the spokesman said.

A St John spokesman told Chris Lynch Media they responded with an ambulance and two rapid response vehicles.

One person has been transported to Christchurch Hospital in a critical condition.

Fire and Emergency crews have also been called to the crash.