Japan's meteorological agency lifted a tsunami advisory around an hour after a 6.9-magnitude earthquake struck off the country's northeastern coast on Saturday, causing no immediate damage or injuries.

The strong quake, which was originally estimated as 7.2 magnitude, hit at 6:09 pm (0909 GMT) in Pacific waters off the Miyagi region with a depth of about 60 kilometres (37 miles), the JMA said, issuing an advisory for tsunami waves of around one metre.

Thousands of households received evacuation warnings over the tsunami alert, which was lifted at around 7:30pm (1030 GMT), prompting municipalities to also end the evacuation measures.

Local utilities and the nation's nuclear authority said the region's nuclear plants did not show any abnormalities after the latest quake, although local railway firms suspended services, including the high-speed Shinkansen bullet trains.

The US Geological Service put the strength of the quake at 7.0 magnitude.

The quake and tsunami advisory come not long after Japan marked a decade since the catastrophic 9.0-magnitude earthquake of March 11, 2011, which triggered a killer tsunami and the Fukushima nuclear meltdown.

The so-called triple disaster affected Japan's northeast, including Miyagi.

Some residents of coastal communities said they had fled to higher ground after the advisory was issued Saturday evening.

"I recalled that day 10 years ago," a man in Ishinomaki city told national broadcaster NHK as he fled to a park on a hill.

"Because of our experience of that day, I moved quickly. My heart is pounding hard," he said.

There were no immediate reports of damage, according to Takashi Yokota, an official of Miyagi prefecture's disaster management office.

Saturday's quake came not long after Japan marked 10 years since the catastrophic 9.0-magnitude earthquake of March 2011
Saturday's quake came not long after Japan marked 10 years since the catastrophic 9.0-magnitude earthquake of March 2011 AFP / Behrouz MEHRI

"We have not received any immediate report of damage or injuries following the earthquake and the tsunami advisory. But we are still collecting information," he told AFP.

The Nuclear Regulation Authority said there had been no reports of abnormality at the area's nuclear facilities, including the crippled Fukushima Daiichi plant, the Onagawa nuclear plant and various smaller facilities and experimental nuclear reactors.

A spokeswoman at Tokyo Electric Power, which is now dismantling the Fukushima reactors, said the facility's cooling system was operating normally.

Last month, the region was also shaken by another strong quake that injured dozens.

One person was subsequently found to have died in the tremor, which meteorologists said was an aftershock of the 2011 quake.

Despite the advisory, the JMA said no clear tsunami was observed after the latest quake, which was also an aftershock of the 2011 quake.

The agency added that more quakes may strike again in the same area particularly in the coming week.

"This is an area that has seen continued, active seismic activities," a JMA seismologist said during a nationally televised briefing.

"Although the tsunami advisory has been lifted, some changes of the ocean surface are possible. Please refrain from going to coastal areas," she said.

Japan sits on the Pacific "Ring of Fire", an arc of intense seismic activity that stretches through Southeast Asia and across the Pacific basin.

The country is regularly hit by quakes and has strict construction regulations intended to ensure buildings can withstand strong tremors.