A person has been critically injured after a vehicle smashed into a power pole in Spencerville last night.

A police spokesman told Chris Lynch Media emergency services were called to the serious crash on Lower Styx Road at 10:25pm.

A St John spokesman said they responded with four ambulances and two rapid response vehicles.

Four patients were assessed at the scene, three were in a moderate condition and one in a critical condition.

All four were transported to Christchurch Hospital the spokesman said.

The serious crash unit was notified and enquiries into the cause of the crash was ongoing.

The road was initially blocked but was now open.