A 6.8-magnitude tremor hit in Japan's Niigata Prefecture just off the coast of the main island on Tuesday. ?Japan's Meteorological Agency reported that the earthquake struck 85 kilometres north-east of the city of Niigata.

Japan's meteorological agency has issued an advisory for a 0.2-1.0 metre tsunami along the northwest coast of Honshu Island.

An evacuation of residents of the northern part of Japan is now underway by state authorities due to the risk of a tsunami devastating the area.

Later in the day, the Japanese Trade Ministry stated that no information regarding any damage inflicted to nuclear power plants, including Fukushima Daiichi, is available following the earthquake. 

A tsunami may have come to Niigata and Yamagata Prefectures, with an expected height of 3 feet, according to the NHK broadcaster.