SYDNEY -- An undersea earthquake with a magnitude of 6.1 has struck near the Pacific island nation of Vanuatu but there were no reports of damage and no tsunami alert was issued.
The U.S. Geological Survey says the quake occurred shortly after midnight Sunday about 226 miles (363 kilometers) east of the Vanuatu capital of Port Vila. It was at a depth of 12.1 miles (19.4 kilometers).
Vanuatu is part of the Pacific "Ring of Fire," an arc of earthquake and volcanic zones stretching from South America through Alaska and down through the South Pacific.
A 7.3-magnitude quake struck near Vanuatu on Dec. 26, causing a tsunami a few inches high but no damage. A 6.5-magnitude quake on March 16 also did not cause any damage.