HONG KONG, May 14 (Xinhua) -- An earthquake with a magnitude of 6.4 jolted 137 km W of Neiafu, Tonga at 04:15:38 GMT on Wednesday, the U.S. Geological Survey said.

The epicenter, with a depth of 243.1 km, was initially determined to be at 18.72 degrees south latitude and 175.28 degrees west longitude.