The shocks were recorded at 21:26 local time (12:46 GMT), the agency specified. The epicenter of the earthquake was located 50 kilometers (31 miles) under the water surface.
Small shocks could be also felt in Tokyo, a Sputnik correspondent reported.
A magnitude 7.3 earthquake rocked Fukushima Prefecture on February 13. It left at least 155 people injured, with no fatalities reported so far.