Three shallow aftershocks have struck near Christchurch this morning, the largest a magnitude 4, GNS Science reports.
The first, a magnitude 4, struck at 12.57am, 20km west of Christchurch near Rolleston, at a depth of 11km.
It was followed by a magnitude 3.4 at 3.07am at a depth of 9km and a 3.7 at 5.10am at a depth of 10km, both also 20km west of Christchurch.
Each was felt in Christchurch.
- Herald Online staff