MOSCOW, October 8 (RIA Novosti) - The Pacific Tsunami Warning Center has issued a tsunami alert for southwestern Pacific countries over a powerful quake in Vanuatu.

The US Geological Survey said Vanuatu was rocked by two quakes in 15 minutes, with a magnitude of 7.8 and 7.3. The Pacific Tsunami Warning Center said the quake was 8.0 on the Richter scale. There were no immediate reports of damage or casualties.

"An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines near the epicenter within minutes and more distant coastlines within hours," the warning said.

The epicenter of the quake was located 373 km (232 miles) northwest of Vanuatu's largest island, Espiritu Santo, at the depth of 35 km (22 miles).

The tsunami watch is in effect for Vanuatu, Solomon Islands, Nauru, Papua New Guinea, Tuvalu, New Caledonia, Fiji, Kiribati, Kosrae, Wallis-Futuna, Howland-Baker.