Japan has been struck by a magnitude-8.8 earthquake off its north-east coast, triggering a four-metre tsunami that washed away cars and buildings along the coast.
In various locations along Japan's coast, TV footage showed severe flooding, with dozens of cars, boats and even buildings being carried along by waters. A large ship swept away by the tsunami rammed into a breakwater in Kesennuma city in Miyagi prefecture, according to footage on public broadcaster NHK.
Officials were trying to assess possible damage from the quake but had no immediate details.
The quake that struck at 2.46pm local time was followed by a series of aftershocks, including a 7.4-magnitude tremor about 30 minutes later. The US Geological Survey upgraded the strength of the first quake to a magnitude 8.8.
The meteorological agency issued a tsunami warning for the entire Pacific coast of Japan. National broadcaster NHK was warning those near the coast to get to safer ground.
The Pacific Tsunami Warning Centre in Hawaii said a tsunami warning was in effect for Japan, Russia, Marcus Island and the Northern Marianas. A tsunami watch has been issued for Guam, Taiwan, the Philippines, Indonesia and the US state of Hawaii.
The quake struck at a depth of six miles, about 80 miles off the eastern coast, the agency said. The area is 240 miles north-east of Tokyo.
In central Tokyo, large buildings shook violently and workers poured into the street for safety. TV footage showed a large building on fire and bellowing smoke in the Odaiba district. Trains were stopped and passengers walked along the tracks to platforms.
Thirty minutes after the quake, tall buildings were still swaying in Tokyo and mobile phone networks were not working. Japan's Coast Guard has set up task force and officials are standing by for emergency contingencies, Coast Guard official Yosuke Oi said.
"I'm afraid we'll soon find out about damages, since the quake was so strong," he said
© Press Association