HONG KONG, Oct. 4 (Xinhua) -- A moderate undersea earthquake measuring 6.0 on the Richter scale occurred at 1246 GMT Thursday in the sea area west of northern Sumatra, according to a bulletin released by the Hong Kong Observatory.

    The epicenter was initially determined to be 2.5 degrees north latitude and 92.9 degrees east longitude, about 430 kilometers southwest of Banda Aceh, Indonesia.

    There was no immediate report of casualties or damage so far.