TOKYO—A strong earthquake hit off the coast of northeastern Japan late Saturday, shaking Fukushima, Miyagi, and other areas, but there was no threat of a tsunami, officials said. Tokyo Electric Power Co. said there were no irregularities at the Fukushima Dai-ichi nuclear plant, which experienced meltdowns following a massive quake and tsunami 10 years ago. There were no immediate reports of irregularities from other nuclear plants in the area, such as Onagawa or Fukushima Dai-ni, government spokesperson Katsunobu Kato told reporters. The Japan Meteorological Agency said the quake had a magnitude of 7.3, raising it from a preliminary magnitude of 7.1. Tokyo Electric Power Co. said that some 860,000 homes were without power as a result of the quake, but electricity was gradually being restored, according to Kato. Kato said there was no danger of a tsunami from the quake. He said that some trains in northeastern Japan had stopped …