As many as 250 civilians are feared dead after an earthquake sent a tsunami crashing into the north of Japan earlier.
Many more are missing, with extensive damage reported across the region. Pictures from local television stations show buildings toppling under pressure from a huge wave of water, with cars, boats, and even roads also swallowed up.
The 8.9 magnitude earthquake struck approximately 250 miles from Tokyo at a depth of 20 miles, shaking the capital, according to the Japan Meteorological Agency.
It was followed by a ten metre wave of water.
The first tremor was recorded at 14:46 local time (05:46 GMT) and was followed by a series of powerful aftershocks.
Seismologists in the country say it is one of the largest earthquakes to hit Japan for at least a century.
Across the Region
Communities across east Asia have been put on high alert following the events in Japan, with evacuations beginning in Taiwan, the Philippines and eastern Russian.
New Zealand and many small Pacific islands – including Tonga and Samoa – could be in danger according to the Pacific Tsunami Warning Centre in Hawaii, while warnings were also issued for the west coast of the Americas, from Mexico to Chile.
Indonesia - which saw the coastline of its Aceh region devastated by a huge Indian Ocean tsunami in 2004 - was braced for waves up to two metres high.
Hawaii ordered evacuations from coastal areas, and authorities urged residents of the US island territory of Guam to move from low-lying regions.
In Tokyo hundreds of thousands of people are stranded as the transport infrastructure, including the vast Metro system, ground to a halt.
The earthquake has wrought havoc for airlines operating in the region, with many flights into Japan cancelled.
Many airlines - including Malaysian Airlines, British Airways, Virgin, China Southern, Korean Air and Jetstar - have diverted or cancelled flights to destinations in the earthquake area.
Condolences and offers of assistance from around the world have been arriving in Japan.
British prime minister David Cameron said: “We have had a terrible reminder of the destructive power of nature, and everyone should be thinking of that country and their people, and I have asked immediately that our government should look at what we can do to help.”
There are more than 17,000 British nationals resident in Japan, while a further 300,000 UK nationals visit the country each year.
At present there are no reported British casualties.
American president Barack Obama added his voice, stating the United States “stands ready” to come to the assistance of its close ally.
“The United States stands ready to help the Japanese people in this time of great trial.
“The friendship and alliance between our two nations is unshakeable, and only strengthens our resolve to stand with the people of Japan as they overcome this tragedy,” Obama said in a written statement released by the White House.