A powerful underwater earthquake struck Friday off Tonga in the southern Pacific, prompting authorities to issue a tsunami advisory that was later lifted. The U.S. Geological Survey said the magnitude 7.3 quake was centered 132 miles east-southeast of Neiafu, Tonga, at a depth of 15 miles.

It predicted strong shaking but said the probability of serious damage or casualties was small.

The U.S. Tsunami Warning System initially issued a tsunami advisory, which is one step below a tsunami warning.

"There is no longer a tsunami threat from this earthquake," said the Pacific Tsunami Warning Center at about 1:30 am.

Tonga's meteorological service urged residents to move inland and boaters to move away from reefs.

"Please move inland immediately until further advised," the service said on its Facebook page.

Seismic activity is fairly common around Tonga, a country with about 100,000 people spread across 171 islands.

An undersea volcano erupted in Tonga in January, killing three people, blanketing its main island with a thick layer of volcanic ash and shooting millions of tons of water vapor high up into the atmosphere.

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