TOKYO (Reuters) - An earthquake with a magnitude of 7.4 jolted islands in the Pacific southeast of mainland Japan on Wednesday and a tsunami warning was issued, the Japan Meteorological Agency said. There were no immediate reports of damage, public broadcaster NHK said, adding the tsunami warning was for waves of up to one metre high for the Ogasawara islands, about 1,000km south of Tokyo. Small waves had already hit one of the islands, NHK reported. The focus of the tremor was about 130km northeast of Chichijima island and about 10km under the sea, the agency said.