Police continue to work with other emergency services and support communities in response to the earthquake which occurred just after midnight.
One casualty has been reported at a collapsed property in Kaikora. Police are also trying to access a property at Mt Lyford north of Christchurch where a further casualty has been reported, which is believed to be a fatality.
Police districts in the North and South Island are working with fire and civil defence to check areas where damage has occurred.
Wellington City Council has advised people not to travel into the city this morning.
Police warn that anyone who does intend coming into the city could experience delays on the motorway as train services are currently suspended. Some roads in the city may not be accessible, and diversions may be in place.
Police urge everyone in the affected areas to continue to listening to advice from the Ministry of Civil Defence and Emergency Management, as well as local Civil Defence services.
Police expect to have a fuller picture of the situation as it gets light.
The Police 111 service is working normally for anyone who wishes to report an emergency.
Issued by Police Media Centre