Tokyo - A massive 8.8-magnitude quake hit the northeast coast of Japan on Friday, shaking buildings in the capital Tokyo, causing "many injuries", at least one fire and triggering a 4m tsunami, NHK television and witnesses reported.
There was also a warning of a 10m tsunami following the quake, Japan's biggest in 7 years.
The public broadcaster showed flames and black smoke billowing from a building in Odaiba, a Tokyo suburb, and bullet trains to the north of the country were halted.
Black smoke was also pouring out of an industrial area in Yokohama's Isogo area.
TV footage showed boats, cars and trucks floating in water after a small tsunami hit the town of Kamaichi in northern Japan.
"The building shook for what seemed a long time and many people in the newsroom grabbed their helmets and some got under their desks," Reuters correspondent Linda Sieg said.
"It was probably the worst I have felt since I came to Japan more than 20 years ago."
Passengers on a subway line in Tokyo screamed and grabbed other passengers' hands. The shaking was so bad it was hard to stand, said Reuters reporter Mariko Katsumura.
The US Geological Survey earlier verified a magnitude of 7.9 at a depth of 15.1 miles and located the quake 81 miles east of Sendai, Honshu. It later upgraded it to 8.8.
The Tokyo stock market extended its losses after the quake was announced. The central bank said it would do everything to ensure financial stability.
Japan's northeast Pacific coast, called Sanriku, has suffered from quakes and tsunamis in the past and a 7.2 quake struck on Wednesday. In 1933, a magnitude 8.1 quake in the area killed more than 3 000 people.
Last year fishing facilities were damaged after by a tsunami caused by a strong tremor in Chile.
Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20% of the world's earthquakes of magnitude 6 or greater. http://www.news24.com/Tags/Topics/japan_earthquake