An earthquake measuring 6.3 in magnitude has hit New Zealand's South Island, hours after an initial quake killed two people. 
The new tremor struck at 13:45pm local time (00:45 GMT) at a depth of 10km (6 miles), northeast of Christchurch, the (BBC) reported. 
A 7.5-magnitude quake, with the same depth, had hit the same area just after midnight, triggering tsunami warnings. 
A large river dammed up by a landslide has now breached its banks sending a "large wall of water" downstream. 
Residents around the Clarence River, one of the largest on South Island, are being urged to move immediately to higher ground. There have been hundreds of strong aftershocks, causing power shortages and cuts in water supply, since the initial quake. 
GeoNet, a government-funded project monitoring earthquakes, said the first earthquake was actually two related tremors, and that aftershocks would continue over the next few weeks and months. 
Authorities have been rescuing and evacuating residents along the east coast. 
Waves of around 2m (6.6ft) hit the coast shortly after the first earthquake. Authorities have since lifted the tsunami alert, but are still warning people to stay away from the shoreline. 
Prime Minister John Key surveyed the affected areas by helicopter on Monday and told reporters that he believed the number of fatalities would remain low. 
Civil defence minister Gerry Brownlee told Radio New Zealand that "it looks as though it's the infrastructure that's the biggest problem, although I don't want to take away from the suffering... and terrible fright so many people have had". 
The quake was also felt in Wellington on the North Island, where the city's central business district (CBD) remained quiet on Monday. 
GeoNet said the first quake was the strongest to have hit New Zealand since a 7.8-magnitude earthquake in 2009 in a remote area of the South Island. 
New Zealand lies on the Ring of Fire, the fault line that circles virtually the entire Pacific Rim bringing frequent quakes and volcanic eruptions. Christchurch is still recovering from a 2011 earthquake that killed 185 people and destroyed the city centre.

Source: QNA