Al Jazeera's Tony Cheng, in Tokyo, said that aftershocks were occurring there, with buildings shaking considerably.
"It doesn't seem to be having any serious affect," he said.
"As I look out of the window there's still a lot of traffic going down the highway.
"It does feel from the aftershocks we are getting here in our hotel that it was a massive quake.
"If that happened a significant distance off the coast, there shouldn't be any significant damage.
"But to shake this building as much as it is at the moment one would imagine there is some structural damage.
"Tokyo is quite far from the centre of the quake, but there may be areas closer which have been badly affected."
Earthquakes are common in Japan - the country experiences 20 per cent of the world's major quakes.