SYDNEY, April 6 (Reuters) - An earthquake of magnitude 6.9 struck northwest of the Pacific island nation of Vanuatu, the U.S. Geological Survey (USGS) said on Wednesday.

The Pacific Tsunami Warning Centre did not issue a Pacific-wide tsunami warning.

A similarly-sized quake struck the same area on Sunday without causing any damage. (Reporting by Byron Kaye; Editing by Clarence Fernandez)

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