The trains were stopped on a wide strip of northeastern Japan on Sunday after more than 100 people were injured in an earthquake that appeared to be a sequel to the devastating earthquake that hit the area in 2011.
The 7.3 magnitude earthquake occurred just before midnight on Saturday and cracked walls, shattered windows and triggered a landslide in Fukushima, the area closest to the epicenter.
The Japan Meteorological Agency said the earthquake was believed to be a replica of the magnitude 9.0 earthquake of March 11, 2011, which caused a tsunami and the worst nuclear accident in the world in 25 years. The agency warned of aftershocks for several days.
The earthquake shook buildings in the Japanese capital, Tokyo, hundreds of kilometers away.
Although hundreds of thousands of buildings lost electricity shortly after the earthquake, which occurred at 2308 local time (1408 GMT), power was mostly restored on Sunday morning.
However, several thousand families remained without water and residents lined up with plastic jugs to receive water from trucks.
The power cuts did not affect any of the COVID-19 vaccines from Pfizer Inc, which arrived on Friday for vaccines that are due to start this week, Chief Cabinet Secretary Katsunobu Kato told a news conference on Sunday morning.
At least 104 people were injured, NHK national television said, including several who suffered fractures, but there were no reported deaths.
There was no tsunami or reports of irregularities at any nuclear power plant. NHK reported that about 160 ml (5 ounces) of water leaked from a pool of spent fuel in the Fukushima Dai-Ni reactor, but that was not a danger.