An earthquake measuring 6.0 on the Richter's scale hit off Tonga at 0339 GMT on Sunday, according to a bulletin released by the U.S. Geological Survey.

The epicenter, with a depth of 41.2 km, was initially determined to be 15.032 degrees south latitude and 173.543 degrees west longitude, 695 km northeast of Nuku'alofa, the Tongan capital.

The quake caused no casualties or damages.

No tsunami alert has been issued by the Pacific Tsunami Warning Center in Hawaii.