A magnitude 7.5 earthquake has struck North Canterbury, near Hanmer Springs, causing extensive damage to areas in the South Island.
Many aftershocks have been felt since the quake.
The 15km deep quake was felt throughout the entire country, as far as Northland, and tsunami warnings have been put in place.
Civil Defence New Zealand has posted a status to Facebook saying, "A tsunami has been generated, the first wave has arrived in the North Eastern Coast of the South Island and it may arrive in Eastern Coast of the North and South Islands of New Zealand shorly (including Wellington, Christchurch and the Chatham Islands."
Police have also been responding to many calls since 12am. They're reminding members of the public to drop, cover and hold during any subsequent earthquake.
They're urging anyone who is on the street to be careful when standing near buildings due to any falling debris. The public is also being advised to move to higher ground or go as far inland as possible.
More updates to come throughout the day.