Japan earthquake map
© JAPAN METEOROLOGICAL AGENCYThe epicenter of the earthquake that occurred on June 25 at 4:47 a.m. is located in Chiba Prefecture
A magnitude 6.1 earthquake struck off eastern Japan early Thursday, the Japan Meteorological Agency said, rocking buildings in the capital Tokyo and surrounding prefectures. No tsunami warning was issued.

The 4:47 a.m. quake, which originated at a depth of about 36 kilometers, registered as lower 5 on nation's shindo seismic intensity scale of 7 in the city of Asahi, Chiba Prefecture. The agency warned that quakes of similar intensity may follow over the next week in areas that experienced strong swaying.

An intensity of lower 5 means people are likely to become frightened and feel the need to hold onto something stable, according to the agency.

"After a shock that felt like something pushing up from below, swaying lasted for 30 seconds to 1 minute," said a male clerk at a convenience store in Asahi. "But nothing fell off shelves and no glasses broke."

A woman in her 80s broke her left leg after she woke during the quake and fell down in her home in Ichihara, Chiba, where tremors measuring an intensity of 4 on the shindo scale were recorded, according to authorities.

KYODO