A warning of a possible tsunami in the South Pacific was issued after a 7.9 magnitude earthquake was registered about 130 miles (209 km) southeast of Nuku'alofa, Tonga, Reuters cited the U.S National Weather Service's Pacific Tsunami Warning Center as saying today. "It is not known that a tsunami was generated," the center said. "An earthquake of this size has the potential to generate a destructive tsunami," it added. The quake occurred at 1818 GMT at a depth of of 6.2 miles (10 km), the U.S. Geological Survey reported.