Wellington, Sep 2 (IANS) A powerful 7.1 magnitude earthquake that hit the east coast of New Zealand's North Island on Friday generated a mild tsunami but caused no damage, authorities said.
A tsunami warning had been issued following the severe earthquake but was cancelled shortly after, EFE news reported.
The Pacific Tsunami Warning Centre said the quake generated waves of about 21 cm for about 16 minutes and recommended to maintain caution in coastal areas.
The quake, one of the strongest to strike New Zealand, occurred at 4.37 p.m.
Its epicentre was 167 km northeast of the town of Gisborne and at a depth of 30.7 km, according to the US Geological Survey (USGS).
Several aftershocks have followed, including one of 6.2 magnitude and aftershocks were expected to continue in the coming months, according to the New Zealand geological agency GNS.
"We would expect a continuing sequence of magnitude fives, magnitude fours to happen in relatively the same location, with that activity spreading out over distance in the coming days and weeks," GNS Science seismologist Bill Fry said.
Frequent earthquakes in New Zealand are due to the country's location on the boundary between two tectonic plates - the Pacific and the Australian.
The country experiences around 14,000 earthquakes each year, most of which are small but around 100-150 are large enough to be felt.
In February 2011, a devastating 6.3 earthquake hit New Zealand's South Island, killing nearly 200 people.