UPDATED: Powerful quake rocks Japan on New Year's day

A major 7.0-magnitude earthquake rocked Tokyo Sunday as Emperor Akihito led Japan's New Year celebrations by urging people to work together in rebuilding the nation from March's quake-tsunami disaster.

The tremor struck at 2:28pm (0528 GMT) with its focus deep at about 370 kilometres (230 miles), Japan's Meteorological Agency said. The US Geological Survey put the depth at 348 kilometres.

Its epicentre was located near Torishima, a northwestern Pacific island about 560 kilometres south of Tokyo.

There were no immediate reports of damage or injury and no tsunami warning was issued.

The mid-afternoon quake swayed buildings in Tokyo and surrounding areas but it did not disrupt the final of the Emperor's Cup football tournament under way at the National Stadium.

"Some people, who were walking, did not seem to notice the quake," a spokesman for Tokyo Disneyland said, adding business went on as usual at the theme park after some rides were automatically shut down.

He did not give the number of visitors on the day but estimated it at several tens of thousands.

Train runs and airline flights in and around the capital area were not affected.

A 9.0-magnitude quake and monster tsunami ravaged the country's northeast on March 11, killing more than 19,000 people, and crippled a nuclear power plant which has been since leaking radiation into the environment.

In a New Year message, Emperor Akihito said: "Our country is now going through difficult times because of the earthquake and other factors."

"But I hope that the people's hearts will always be with the afflicted, and that everyone will persevere and work together to build a brighter tomorrow."

Wishes for the nation's recovery appeared to have dominated as the new year started in Japan with tens of thousands of people flocking to Shinto shrines and Buddhist temples to offer money and pray for good fortune.