The quake struck just before dawn and was felt over much the country. The tsunami warning was issued about 90 minutes later. Evacuations were also advised on the East Cape region of the northern island, but the warning has since been lifted.
No injuries have been reported but several homes in the Gisborne region have been damaged. Private water supplies in the area have also been damaged.
Local seismologist John Ristau said the nearly minute-long quake was the biggest to hit the East Coast of North Island in 20 years. But the 2007 quake which measured 6.8 and was closer to Gisborne likely caused more damage.
At least 140 aftershocks have occurred, most registered a magnitude 3 or higher.
Source: GNA/News Ghana