A 5.6 magnitude quake hit 40 km west of Milford Sound just before 10pm today.
Photo: GeoNet
GeoNet said it was 5km deep and was reported as being felt by more than 2000 people.
It was followed seven minutes later by a magnitude 4 quake, at a depth of 5km, in the same area.
The second shake was initially reported as magnitude 3.5 and later revised.