A 5.4 magnitude aftershock rattled New Zealand capital of Wellington overnight, following a 6. 5 magnitude earthquake on July 21.

The earthquake, which the New Zealand government geological agency GNS Science classified as severe intensity, hit 20 km east of upper South Island town of Seddon at a depth of 12 km at about 1:07 am local time Monday (13:07 GMT Sunday).

It's one of the largest aftershocks to hit the region since a 6. 5 magnitude earthquake hit the Cook Strait last Sunday, damaging about 30 Wellington buildings.

About 25 people reported minor injuries following the 6.5 magnitude tremor.

Earthquake Commission (EQC) has received more than 2,000 claims since last Sunday, with 75 percent coming from the North Island and 25 percent from the South Island.