WASHINGTON (Reuters) - A magnitude 6.0 earthquake that struck off North Korea in the Sea of Japan does not appear to have been caused by a nuclear test, the Pentagon said on Wednesday, citing initial reports.

Major Jamie Davis, a Pentagon spokesman, said initial indications showed that the earthquake was not caused by a North Korean nuclear test because of the location and depth of the quake.

Davis added that the Pentagon would continue to study the seismic activity.