A 6.5-magnitude quake hit waters off Vanuatu early Friday, the United States Geological Survey said. There was no immediate reports of casualty or damage.

The epicenter of the undersea quake, which struck from a depth of 10 kilometers at 0:18 a.m. on Friday local time (1318 GMT, Thursday), was traced 78 kilometers east-southeast of Lakatoro, Vanuatu.

The Hawaii-based Pacific Tsunami Warning Center did not immediately issue a tsunami warning or watch in relation to the quake.

Vanuatu lies on the so-called Pacific "Ring of Fire," an arc of earthquake and volcanic zones where continental plates collide producing frequent seismic activity.