A strong earthquake Friday struck the same Japanese coast devastated by last year's massive quake and tsunami, generating small waves but no immediate reports of heavy damage. Several people along the northeastern coast were reportedly injured and buildings in Tokyo and elsewhere swayed for several minutes.
The earthquake had a preliminary magnitude of 7.3 and struck in the Pacific Ocean off the coast of Miyagi prefecture at 5:18 p.m., the Japan Meteorological Agency said. The epicentre was 10 kilometres beneath the seabed and 240 kilometres offshore.
The area was shaken by repeated, smaller aftershocks, the agency said.
After the quake, authorities issued a warning that a tsunami potentially as high as 2 metres could hit. Sirens whooped along the coast as people ran for higher ground.
Ishinomaki, a city in Miyagi, reported a tsunami one metre high and other towns reported smaller tsunamis.
About two hours after the quake struck, the tsunami warning was cancelled. The Pacific Tsunami Warning Center earlier said there was no risk of a widespread tsunami.
Aiko Hibiya, a volunteer for the recovery in Minami-Sanriku, a coastal town devastated by last year's tsunami, said she was at a friend's temporary housing when the quake struck.
"It shook for such a long time," she said.
She said other volunteers who had been in coastal areas were evacuated to a square and a parking lot as they waited for the tsunami warning to be lifted.
Japan has barely begun to rebuild from last year's magnitude-9.0 earthquake, which triggered a tsunami that swelled to 20 metres high in some areas, ravaging dozens of coastal communities in Miyagi and elsewhere. About 19,000 people were killed and some 325,000 people remain displaced from their homes, living in barracks and other temporary quarters.
Miyagi prefectural police said there were no immediate reports of damage from Friday's quake and tsunami, although traffic was being stopped in some places to check on roads.
Public television broadcaster NHK reported that five people were injured, including a 75-year-old woman in Miyagi who fell while fleeing the tsunami. Police said they could not immediately confirm those reports.