Updated | Tsunami strikes New Zealand after powerful tremor

A tsunami has struck New Zealand’s east coast after a powerful earthquake hit the South Island just after midnight.

The US Geological Survey said the magnitude-7.4 quake hit 59 miles (95km) from Christchurch, which is still recovering from the 2011 earthquake that killed 185 people and destroyed many buildings.

The tsunami arrived in the north-eastern coast about two hours later. Officials said the first waves may not be the largest, with tsunami activity possible for several hours. The New Zealand Civil Defence advised residents on the South Island's east coast to seek higher ground over fears that the earthquake could cause a tsunami. 

Civil defence issued a tsunami warning for the entire east coast and said it was “assessing [the] situation with assistance of scientific advisers and civil defence groups”.

The quake struck at about midnight local time (12:00 CET) with the scale of damage and extent of injuries still being unclear.

A gauge at Kaikoura, 181 km (112 miles) north of Christchurch, measured a wave of two metres (6ft 5ins).

According to the New Zealand Herald, said the tremor was felt all the way to Wellington, where sirens sounded and people fled buildings into the streets, some of them crying.

Early reports suggested some houses in Cheviot town, near the epicentre, have been damaged.

But Chris Hill, a fire officer in Cheviot, said officials had gone door to door evacuating residents and found "everyone seems okay".

He told RadioNZ: “There's a lot of debris in houses, but at this stage it doesn't look like anything too bad has happened.”

New Zealand lies on the notorious Ring of Fire, the line of frequent quakes and volcanic eruptions that circles virtually the entire Pacific rim.

Christchurch is still recovering from the 2011 earthquake that killed 185 people and destroyed the city centre.