A one-metre-high tsunami hit northeast Japan Friday after a powerful undersea quake struck off the coast, sending thousands fleeing to safety in a region that was devastated in last year's quake-tsunami disaster.

Broadcasters urged residents along the shoreline to remember the 2011 catastrophe and move to higher ground when the initial tremors rocked the region.

Telephone systems jammed up with the sheer volume of calls, complicating officials' efforts to evacuate exposed areas until the tsunami warning was lifted two hours later.

Meteorologists said the wave swept ashore just after 6 pm (0900 GMT) in Ishinomaki, a city badly hit by the 2011 quake-generated tsunami that wrecked a large swathe of coast, killing thousands.

There were no immediate reports of any fatalities following the quake, which had a magnitude of 7.3, according to the United States Geological Survey.

Several smaller tsunamis were also recorded, including a 40-centimetre wave at Soma, a city that lies just outside the evacuation zone declared around the Fukushima nuclear plant after meltdowns there last year.

Operator Tokyo Electric Power (TEPCO) told AFP there were no reports of any problems at the crippled plant.

Broadcaster NHK reported 5,000 people had fled in Miyagi prefecture, a region devastated in last year's disaster.

Officials in Minamisanriku, Miyagi prefecture, said they were doing their best to get people to safety, but were running into technical difficulties.

"We are now calling on people to evacuate to higher ground," town official Ryuichi Omori told AFP shortly after the quake struck.

"It's already pitch dark here. Phones -- both landlines and mobiles -- are not going through now, which makes it difficult to see people's movement.

"The quake was not so big, although it felt very long. It was not big at all compared with last year's earthquake. The town office is now setting up a disaster taskforce."

A presenter on state broadcaster NHK repeatedly urged viewers to get to safety after the initial tremors, which set Tokyo buildings swaying violently.

"Remember last year's quake and tsunami," he said. "Call on your neighbours and flee to higher ground now!"

The 7.3 quake struck 36 kilometres (23 miles) under the Pacific, the US Geological Survey said, with an epicentre 284 kilometres (176 miles) east of Sendai.

It was followed by a 6.2 aftershock and another tremor measuring 5.5.

The Japan Meteorological Agency issued a tsunami warning, one notch lower than a tsunami alert, for the Pacific coast of Iwate, Fukushima, Aomori and Ibaraki prefectures.

The agency lifted the warning around two hours later.

A spokesman for TEPCO said the quake had passed off without incident at the wrecked power station.

"No abnormalities have been recorded on instruments at Fukushima Daiichi nuclear plant's six reactors," a TEPCO spokesman said.

"All workers were ordered to take shelter inside buildings at the Fukushima plant.

"No abnormalities were confirmed with the radiation monitoring posts at the Fukushima plant. No abnormalities were seen with the water processing facilities."

NHK reported 10 people were hurt, including a 36-year-old woman in Ibaraki prefecture, who suffered injuries after a closet fell on her. None of the injuries was thought to be serious, the broadcaster said.

Transport systems in the region were briefly interrupted, but normal service was resumed a short time later.