An earthquake with an estimated magnitude of 6.1 struck off the coast of Chichijima island, part of the Ogasawara archipelago south of Tokyo, at 6:08 a.m. on Jan. 4, the Japan Meteorological Agency said, Asahi Shimbun reported.
It registered an upper 5 on the Japanese seismic intensity scale of 7 on Hahajima island and 4 on Chichijima island.
The earthquake had a focal depth of about 77 kilometers, officials estimate.
Following the temblor, the government set up a liaison office at the premier's office to gather information, Kyodo News reported.
The agency said there was no risk of a tsunami. There were no reports of injuries or significant structural damage as of 7 a.m., Tokyo police and firefighters said.
The focus in waters near the island was at a depth of 77 kilometers.
A weather agency official warned that further earthquakes of up to upper 5 on the intensity scale could occur over the coming seven days, especially in the next two to three days.
The Ogasawara Islands are located about 1,000 km south of the capital and are administered by the Tokyo metropolitan government. Ogasawara village in the chain has a population of about 2,500 people.
The last time an earthquake of this size hit the area was when a temblor struck west of the chain in May 2015, leading to shaking of an upper 5 intensity on Hahajima island.
MP/PR