No damage or casualties were reported, but it was the latest strong tremor this year in a nation constantly bracing for a massive earthquake.

Tsunamis measuring up to 50 centimetres (20 inches) brushed the east coast of northern Japan about one hour after the undersea quake hit at 6:39 am, local officials said.

The focus of the shallow quake was located about 350 kilometers (215 miles) off Japan's main Honshu island, the meteorological agency said.

Some of the highest waves were observed in Ofunato, a city in Iwate prefecture in the northern part of Honshu.

"There has not been any report of damage so far," Ofunato disaster prevention official Haruki Ito told AFP.

"But we are now asking people to check aquaculture equipment. This is the season for oyster and scallop farming. We may hear of some damage later from some oceanic facilities," he said.

The coastal village of Tanohata in Iwate advised some 900 people to evacuate, village official Masatsugu Kikuchi told public broadcaster NHK by telephone.

"It was not compulsory but hundreds of residents evacuated their homes as a precaution," he said.

The village later allowed people to return home after the meteorological agency lifted the tsunami warning, he said.

The quake triggered an automatic suspension of the Tohoku line of the Shinkansen bullet train, but the service resumed normal operations shortly afterwards, said a spokesman for East Japan Railway.

All the tsunami warnings were cancelled two hours after the quake struck, the meteorological agency said.

Japan has one of the world's most advanced tsunami early warning and emergency response systems. Within minutes of a tremor, research centers predict whether there is a risk of a tsunami, sometimes announcing that the waves will be only centimeters (inches) high.

People living near the coast are taught to rush for higher ground if a major tsunami is detected. Several coastal towns have constructed tall ferro-concrete buildings where residents can seek shelter.

A massive undersea quake off Indonesia last December triggered a tsunami that crashed into coastlines around the Indian Ocean, leaving more than 200,000 people dead.

Japan endures 20 percent of the world's major earthquakes.

Last year, 51 people were killed and hundreds injured in a 6.8-magnitude quake in the Niigata region, 200 kilometers northwest of Tokyo.

The Sendai area in August was hit by a 7.2-strong quake, which shut down traffic but caused little other damage.

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