Authorities issued a tsunami alert for the northeast coast Friday after a powerful 7.3-magnitude undersea earthquake struck, setting buildings in Tokyo swaying violently.

Commuters at Sendai Station in Miyagi Prefecture consult their cell phones and wait for trains to resume service after a strong earthquake with a magnitude of 7.3 jolted northeastern and eastern Japan. KYODO PHOTO

They said tsunami up to 1 meter high could sweep ashore in areas badly hit by the March 2011 tsunami that devastated a large swath of the Tohoku region coast, killing thousands.

A 1-meter wave was seen in the Ayukawa district in Ishinomaki, Miyagi Prefecture, shortly past 6 p.m., NHK said. In addition, a 20-cm wave was logged by a tsunami gauge off Kinkazan in Miyagi.

It wasn't immediately clear if the waves caused any damage.

Residents in cities along the Sanriku coast were advised to evacuate to higher ground.

Those include Rikuzentakata, Ofunato, Yamada in Iwate Prefecture, as well as Miyagino and Wabayashi wards in Sendai and Ishinomaki and Iwanuma in Miyagi Prefecture.

Telephone operator NTT said the network in the areas was jammed with the weight of calls.

A presenter on NHK repeatedly told viewers to get to safety.

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

The U.S. Geological Survey put the quake's magnitude at 7.3. It said the temblor struck a relatively deep 36 km under the Pacific.

The epicenter was 284 km east of Sendai, or 459 km northeast of Tokyo, according to the USGS.

There was no threat of a Pacific-wide tsunami, U.S. monitors based in Hawaii said. Officials in both Indonesia and the Philippines said there was no threat of a localized tsunami.

Tokyo Electric Power Co. said there were no reports of any problems at its crippled Fukushima No. 1 nuclear plant.

"No abnormalities have been recorded on instruments at the Fukushima No. 1 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."

Prime Minister Yoshihiko Noda rushed to his office to monitor the situation.

East Japan Railways Co. (JR East) temporarily suspended all services in Miyagi Prefecture.

Bullet train services on the Tohoku and Joetsu shinkansen lines were also halted to check for damage.

The Tokaido Shinkansen Line briefly suspended services between Tokyo and Odawara, Central Japan Railway Co. (JR Tokai) said.

Haneda Airport in Tokyo was reported to be operating normally but Sendai airport was closed.

The tsunami warning was lifted at around 7:20 p.m.