A 7.4-magnitude earthquake off the eastern coast of Japan on Wednesday did not cause any issues of safety concern at the three nuclear power plants in the area, including the Fukushima Daiichi Nuclear Power Station, the country's Nuclear Regulation Authority (NRA) told the International Atomic Energy Agency (IAEA) on Thursday.

"Deficiencies" were found at some of the nuclear facilities after the quake and the operators were dealing with them, the Japanese nuclear regulator told the IAEA, but as of 04:30 UTC, March 17, there were no reports of issues giving rise to safety concerns at the nuclear sites located in the region.

The NRA earlier informed the UN nuclear agency that the tremor had not caused elevated radiation levels at the plants.

The quake occurred at a depth of 60 kilometers, 57 km off the coast, the Japan Meteorological Agency (JMA) said, in the same region that was devastated by the magnitude-9 temblor 11 years ago that triggered the Fukushima nuclear disaster, which killed nearly 16,000 people.