WELLINGTON, May 3 (Xinhua) -- A very strong earthquake of magnitude 8.0 struck off the Pacific Island nation of Tonga early Thursday, reports reaching here said.

    The reports quoted the US Geological Survey (USGS) as saying that the quake struck at 4:26 am local time (1526 GMT) in the middle of the islands that make up Tonga.

    The epicenter was 155 kilometers south of Neiafu island and 160km northeast of Nuku'Alofa, the main island.

    The quake was recorded 16 kilometers below the surface.

    There have been no reports about casualties, but the U.S. National Weather Service issued tsunami warning after the strong quake struck off the Pacific Island nation of Tonga. Enditem