A state of emergency has been declared in Christchurch, New Zealand after a large 7.1 magnitude earthquake rocked the country's 2nd largest city this morning.

The magnitude 7.1 quake occurred at 4.35am, 30 kilometres west of Christchurch, at a depth of approximately 10 kilometres.

There have been several aftershocks, the strongest at 5.2 magnitude.

No tsunami warning was issued following the earthquake.

This report from Radio New Zealand.