SINGAPORE – An earthquake with a magnitude of 6.6 struck deep in the Pacific Ocean on Sunday about 525 km (328 miles) south of Suva, Fiji, the U.S. Geological Survey said.

The USGS initially estimated the magnitude at 6.8 and revised it to 6.6. It reported a second earthquake of magnitude 6.1 about 10 minutes later, further south.

The second earthquake was 606 km (379 miles) deep, USGS said. No tsunami warning was issued by the Pacific Tsunami Warning Center.