A powerful earthquake has rocked Japan's north-east coast, leaving two million people without power and triggering a Tsunami warning.
Wednesday's tremor registered magnitude 7.3, public broadcaster NHK reported. It shook large parts of eastern Japan, including the capital Tokyo, where buildings shook violently.
The Japan Meteorological Agency said the earthquake struck 60 kilometres below the sea at 11.36pm local time. A tsunami alert was issued for Miyagi and Fukushima prefectures.
Japan’s Air Self-Defense Force said it dispatched fighter jets from the Hyakuri base in Ibaraki prefecture, just south of Fukushima, for information gathering and damage assessment.
NHK said there were reports of fire, damage to buildings and falling rocks in Iitate town in Fukushima. There was no word on any casualties.
Japan's Tokyo Electric Power Company Holdings (Tepco) said two million homes in the Kanto region were without power in the aftermath of the earthquake.
Tepco, which operates the Fukushima Daiichi nuclear plant that suffered meltdowns after the 2011 quake and tsunami that destroyed its cooling systems, said workers were checking for potential damage,
There were no immediate reports of any casualties.
East Japan Railway Co. said most of its train services were suspended for safety checks. Some local trains later resumed service.
A Tohoku Shinkansen express train partially derailed between Fukushima and Miyagi due to the quake, but nobody was injured, NHK said.
Prime Minister Fumio Kishida told reporters that the government was assessing the extent of damage and promised to do its utmost for rescue and relief operations.
“Please first take action to save your life,” Mr Kishida tweeted.