Shaking buildings in Tokyo, the temblor's epicenter was recorded off 81 km (50 miles) North of the capital. It struck the area at 11:19 am (0219 GMT), USGS reported.
According to reports, the quake did not disrupt the emergency crews who are working to cool crippled reactors around the clock at a nuclear plant hit by a devastating earthquake and tsunami last month.
There were also no immediate reports of any damage or casualties from the latest strong quake.
Related articles:
Japan Earthquake, April 12, 2011: Another strong aftershock rocks Eastern Honshu
Japan Earthquake, April 11, 2011: A strong M7.1 quake hits Japan anew
Japan Earthquake 2011 Update: Strong aftershock rocks Japan on April 7
