The earthquakes triggered massive landslides
At least six people are dead and more than 140 injured after a powerful earthquake struck northern Japan, triggering landslides.
The 7.2-magnitude quake was centred on Iwate - a rural mountainous region on Japan's main island, Honshu.
Military helicopters are taking in supplies and flying the injured to hospitals. A landslide at a hot spring reportedly buried seven people.
And a small amount of radioactive water was leaked at a nuclear power station.
But officials said there was no danger to the public from the minor spillage at the facility in Fukushima.
Prime Minister Yasuo Fukuda said: "Our most important task is to save as many lives as possible, and we are doing the best we can."
Rescuers are scrambling to reach seven people buried by a landslide that engulfed a hot spring resort in Komanoyu.
A construction worker died after being hit by falling rock at a dam and a man hit by a lorry after running out of a building during the tremors was also killed.
Landslides claimed the lives of two more construction workers in Kurihara and killed one more person in Iwaki.
Another body was reportedly found in a smashed vehicle in the mountains.
All high-speed bullet trains in the area were automatically shut down.
Seismologists had issued advance warning of the earthquake - which was followed by more than 150 aftershocks - moments before it struck around 0845 (2343 GMT on Friday).
Footage from NHK television showed surveillance cameras in the city of Sendai being shaken violently for about 30 seconds.
Japan is one of the world's most earthquake-prone countries and experiences thousands of minor tremors each year.
An earthquake last year in central Japan caused a small radioactive leak from the Kashiwazaki-Kariwa nuclear plant.