Powerful earthquake hits New Zealand

A powerful earthquake has struck New Zealand's South Island around 90 kilometres north of Christchurch. A tsunami warning has been issued, calling on people on the east coast to move inland and find higher ground. The 7.4 magnitude tremor, which struck just after midnight local time, was felt across a large area. Power was knocked out in some areas and people rushed out into the streets - but there were no immediate reports of casualties.