New Zealand on tsunami alert following huge 7.1 magnitude earthquake 100 miles off North Island

UPDATE 12.01 2 SEPTEMBER: Tsunami warning cancelled by authorities.

The US geological Survey (USGS) says a 7.1 magnitude earthquake has struck 105 miles off the North Island of New Zealand.

Initially a tsunami alert was not raised but some reports are now warning of the possibility of strong tsunami currents and surges, according to AFP. The quake occurred at about 4.40am local time on Friday morning (2 September) at a depth of 19 miles.

New Zealand's Ministry of Civil Defence issued a "tsunami potential threat advisory" for all the country's coastal areas. According to a statement: "(The ministry) and scientific advisors are in the process of assessing the situation to determine the severity of the threat to New Zealand."

Residents of some areas have been told to evacuate and find higher ground. Small 30cm tsunamis have been registered at some points on the coast but there are warnings larger ones could follow. The risk could last for several hours but the Americas are not thought to be at risk.

The earthquake comes a week after an earthquake in Amatrice, Italy, killed at least 292 people. New Zealand was shaken by a 6.0 earthquake in 2011 which killed 185 people in Christchurch.