Japanese earthquake: Eyewitness accounts
A massive earthquake has hit the north-east of Japan, triggering a tsunami that has caused extensive damage.
Japanese television showed cars, ships and even buildings being swept away by a vast wall of water after the 8.9-magnitude earthquake.
The quake has sparked fires in several areas including Tokyo, and numerous casualties are feared.
Here BBC News website users in Japan recount their experience of the moment the quake struck.
Mike Hall, Hokkaido
I live in Hakodate, which is on the southern most peninsular of Hokkaido.
We have been really lucky, my apartment was shook up for several minutes, a few things fell over etc but there was no major damage.
It is very much like a swaying rolling motion, with jolts that really put the fear of God in you.
Initially, I didn't pay any attention as we've had earthquakes before. But this time, it went on for longer and there were several big aftershocks. The last one was about an hour ago (1000 GMT).
Power and water supplies are fine at the moment and cell phones and the internet seem unaffected. But we have a major tsunami warning in effect.
The bay area of the city has been flooded, though I'm not sure how badly.
We haven't had any visits from local emergency wardens or city officials. Most of the information has come through the various news broadcasts
I have never felt such strong quake in my life.
My flat is on the fifth floor (British fourth floor) and the building shook slowly at first, then more and more violently. It was really scary.
TV is showing a fire in a tall building in the Odaiba area in Tokyo, and also tsunami waves carrying lorries and cars. It looks like there are more fires breaking out in Sendai, a major city in northern Japan.
Until a few minutes ago I was with neighbours who jumped out of the building and shared what little information we had and consoled each other.
Lifts have stopped in our building, and I guess have in most buildings. There are still aftershocks every few minutes.
Although we're far from northern Japan, the quake here was very big.
The first quake was very long - everyone in the office was screaming. Then we had another long one about 30 minutes after that. Paper and items were falling off the desks. We can hear the walls. We can hear the walls going back and forth.
Things have started to calm down now and some people have started to get back to work.
Transportation has all stopped. The company has asked us to stay in the office.
Robert Koch, Tokyo
Everything that is meant to be inside is now outside. My beloved audio system is trashed as is the CD collection.
Thank goodness it did not happen at midnight with my four-year-old son at home.
None of the trains here are running, buses seem to be fine and no-one here has been hurt. It was just really scary being in a high-rise building during an earthquake. My flat looks like a bomb has hit it.
There is almost a buzz of excitement around. I live about 20 minutes away from central Tokyo. Being a South African, one is not very used to ground that ripples and wobbles under your feet.
Jeffrey Balanag, Higashi-Shimbashi, Tokyo
The quake shook and rolled our building in Shiodome Sumitomo Building.
We are stuck in our offices because elevators are stopped. We are watching the TV which is showing the tsunami rushing landward.
The trains have been stopped. We can see Yurikamome Line and JR Yamanote Line stopped.
We can also see fires. You can see the fires across the bay in the Odaiba area.
There is no panic but I am almost seasick from constant rolling of the building.