A 5.6-magnitude earthquake struck central Japan, the country's Meteorological Agency reported.
The epicenter was near Tokyo, at a depth of 20 kilometers.
On the Japanese seismic scale, the intensity was rated 6, strong enough to damage buildings.
Seconds before, the national early warning system activated, sounding alarms on mobile phones even in silent mode.
In Tokyo, furniture shook and dishes fell from shelves.
A tsunami warning was briefly issued but canceled minutes later.
