A 7.3-magnitude earthquake shook Japan early Saturday, the U.S. Geological Survey reported.

The quake was off the Fukushima region of Japan, 231 miles east off the island of Honshu.

It was 6.2 miles deep, officials said, hit at 3:10 a.m. Saturday local time and was felt 300 miles away in Tokyo.

The Japan Meteorological Agency reported a one-foot tsunami was observed after it issued a yellow-colored warning Saturday morning, meaning a small tsunami could reach the coast at Fukushima, site of Japan's 2011 nuclear power plant disaster.