Big earthquake strikes near Christchurch in New Zealand

An earthquake with a magnitude of 7.4 struck 57 miles north-northeast of the city of Christchurch, New Zealand just after midnight (11.02 a.m. GMT Sunday), the US Geological Survey said.

Christchurch is the biggest city on New Zealand's South Island. A 6.3 quake there in February 2011 killed 185 people and caused widespread damage.

The US Pacific Tsunami Warning Center said there was no tsunami threat from Monday's quake.

This story is developing.