A strong earthquake measuring 6.6 magnitude on the Richter scale struck in the western Pacific off Papua New Guinea early Sunday, the US Geological Survey reported. The tremor did not immediately prompt any tsunami warnings by the US National Weather Service's Pacific Tsunami Warning Center or the Japan Meteorological Agency. The Intergovernmental Oceanographic Commission Tsunami Program, which is affiliated with the United Nations, likewise said historical data suggests there is "no destructive widespread tsunami threat." "However, earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a hundred kilometers of the earthquake epicenter," the IOC said in a bulletin. "Authorities in the region of the epicenter should be aware of this possibility and take appropriate action." The quake was centered 70 kilometers (43.5 miles) deep under the ocean floor, the US Geological Survey said. It happened shortly after 6 a.m. Sunday (4 p.m. ET Saturday). The epicenter was about 33 kilometers south-southeast of Taron, in the eastern part of Papua New Guinea. The island nation's capital of Port Moresby was some 850 kilometers away. There were no immediate reports of damage due to the quake.