Tokyo: A metre high tsunami wave hit the coast of northeastern Japan after a strong earthquake shook buildings as far as Tokyo, public broadcaster NHK said on Friday.
The earthquake had a preliminary magnitude of 7.3, the US Geological Survey said, adding that there was no risk of a widespread tsunami. That was revised from an earlier estimate of 7.4.
A warning for a one-meter tsunami was issued for the coast of Miyagi Prefecture in northeastern Japan, which was hit by a devastating earthquake and tsunami in March 2011. The warning was later lifted.
That quake triggered fuel-rod meltdowns at the Fukushima nuclear plant, causing radiation leakage, contamination of food and water and mass evacuations in the world's worst nuclear crisis since Chernobyl in 1986.
The government declared in December that the disaster was under control, but much of the area is still free of population.
Tokyo Electric Power Co, the operator of the Fukushima nuclear plant, reported no irregularities at its nuclear plants after the latest quake.
Indian Ambassador to Japan Deepa Gopalan said that was no need to worry. "It was fairly intense and the duration was long. There are warnings. In Tokyo there is no cause to worry. We will find out if there are Indians in that area. Indian community is mostly in Tokyo and surrounding areas, far from epicentre," said Gopalan.
Narita airport outside Tokyo was back in action after a brief closure for safety checks. Last year's quake, which measured 9.0, triggered fuel-rod meltdowns at Fukushima, causing radiation leakage, contamination of food and water and mass evacuations. Much of the area is still deserted.
The government declared in December that the disaster was under control. "Citizens are now escaping to designated evacuation centres and moving to places on higher ground," office worker Naoki Ara said in Soma, 30 km (18 miles) from the Fukushima-Daiichi plant.
Prime Minister Yoshihiko Noda cancelled campaigning in Tokyo ahead of a December 16 election and was on his way back to his office, but there was no immediate plan to hold a special cabinet meeting. Public spending on quake-proofing buildings is a big election issue.
Japanese were posting photos of their TV screens with tsunami warnings on Facebook, asking each other whether they're safe, confirming their whereabouts. "It shook for a long time here in Tokyo, are you guys all all right?" posted Eriko Hamada, enquiring about the safety of her friends.
Phone lines were overloaded and it was difficult to contact residents of Miyagi. "Owing to the recent earthquake, phone lines are very busy, please try again later," the phone operator said. The yen rose against the dollar and the euro on the news, triggering some safe-haven inflows into the Japanese currency.