A powerful earthquake has shaken northern Japan, injuring at least 90 people, as its force shattered windows and set off fires in an area hit by a deadly tremor just a month ago.
Officials say the earthquake, measuring 6.8 on the Richter scale, struck the north of the main Japanese island of Honshu as most people were asleep, and cut off power to around 10 thousand homes.
The quake didn't trigger a tsunami warning and officials say they've detected no problems in nuclear power plants in the affected area, some of which were shut down manually.