According to the statement, the epicentre of the earthquake was located at the depth of 50 kilometres (over 30 miles) in the southern part of the prefecture.
The tremors were felt in 14 prefectures, the agency said.
There are no reports about victims and damages caused by the quake. No tsunami alert was declared.
Japan is located in a seismically active zone known as the Ring of Fire and regularly suffers from powerful earthquakes. The 2011 9.0-magnitude earthquake and the following tsunami killed over 15,000 people and caused the Fukushima nuclear plant disaster.