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A day after Tonga was hit by giant waves following the eruption of a volcano in the ocean off its coast, a 6.1 magnitude earthquake has struck the island of Papua New Guinea, the US Geological Survey (USGS) has said.

The epicenter of the quake was located in the autonomous Bougainville region, at a depth of 408 kilometers (253 miles), according to the agency. The European Mediterranean Seismological Centre (EMSC) also registered the quake, putting its magnitude at 5.8. There have so far been no reports either of casualties or significant damage.

Papua New Guinea, a country of nine million, occupies the eastern half of the island of New Guinea and a group of smaller islands in Melanesia, north of Australia.

Papua New Guinea is located some 4,700 kilometers (2,920 miles) southeast of Tonga, which was hit by a tsunami on Saturday, after an offshore volcanic eruption. The eruption sent huge waves right across the Pacific, with reports of boats being damaged coming from as far afield as New Zealand and California. Tsunami warnings were issued for Japan, Hawaii, Alaska, and the US West Coast. The tsunami threat has now receded, but Tonga remains covered in an ash cloud, which is preventing surveillance aircraft from assessing the damage.