An earthquake with a preliminary magnitude of 7.6 has struck in the South Pacific near the island nation of Vanuatu and a tsunami warning has been issued. According to AP, the U.S. Geological Survey says the quake was about 140 miles south of Vanuatu's capital, Port Vila. It struck Sunday just after midnight about 15 miles below the ocean surface. There were no immediate reports of damage or injuries, and no more details were immediately available. The Pacific Tsunami Warning Center said a tsunami was possible based on the strength of the earthquake. It was not immediately confirmed whether a tsunami had occurred. The warning area covered Vanuatu, New Caledonia and Fiji.