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An earthquake with a magnitude of 7.8 has rocked New Zealand after striking near Christchurch, triggering a tsunami warning for the entire east coast
The quake struck 57 miles north-northeast of the city just after midnight local time on Monday and shook much of the country.
People who live along the east coast have been told to retreat to higher ground immediately, with emergency officials warning that waves as high as 16ft are possible in some areas.
It also warned the tsunami threat could last hours and the first wave may not be the biggest.
The magnitude was initially measured at 7.4 but later adjusted to 7.8 by the US Geological Survey.
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.