A strong earthquake has struck off the coast of north-eastern Japan shaking Fukushima, Miyagi and nearby areas.

Tokyo Electric Power Company said there were no irregularities at the Fukushima Dai-ichi nuclear plant, which experienced meltdowns following a massive quake and tsunami 10 years ago.

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 said that some 860,000 homes were without power as a result of the quake but electricity was gradually being restored.

Government spokesman Katsunobu Kato said there was no danger of a tsunami from the quake. He said that some trains in north-eastern Japan had stopped running and that other damage was still being checked.

Video from public broadcaster NHK TV showed some pieces of a building wall had broken off and fallen to the ground, and pieces of glass were scattered at a store.

Items fell off shelves because of the shaking, NHK said. NHK aerial footage showed a portion of a highway blocked by a landslide in Soma, a city in Fukushima prefecture.

Mr Kato said there were several reports of minor injuries from the quake, such as a man getting hit by a falling object.

The Japan Meteorological Agency said the quake was centred about 37 miles beneath the ocean.

Prime Minister Yoshihide Suga headed into his office immediately after reports of the quake, and a crisis centre was set up there.

The same north-eastern area was hit by a quake, tsunami and nuclear disaster in March 2011. Experts warned of aftershocks over the next several days, including possibly larger quakes.