The epicenter was about 229 km (142 miles) south-southeast of Katsuura, at a depth of 10 km (6 miles), according to the agency.
The tremor was felt throughout Chiba, and eastern parts of Kanagawa, Shizuoka, and Tokyo prefectures, local sources reported.
There have been no initial reports of damage or casualties as a result of the earthquake. (ILKHA)