Rescue efforts are under way in south-western Japan to help victims of a powerful earthquake that hit the region a day after an earlier tremor.
Some 20,000 troops are being deployed in the operation in Kyushu region after the magnitude-7.3 quake at 01:25 on Saturday (15:25 GMT Friday).
At least 15 people have been killed and hundreds injured, media reports say.
Dozens of people are feared trapped in the rubble of collapsed buildings. The quake on Thursday killed nine people.
Roads have been damaged and big landslides have been reported over a wide area. Some 200,000 households are now without power.
Japan's nuclear authority said the Sendai nuclear plant was not damaged.
A small eruption occurred at Mt Aso following the tremor, media reports say.
Gavin Hayes, a research geophysicist with the US Geological Survey (USGS) in Colorado, told the BBC the latest earthquake would hamper the earlier rescue operation that was already under way.
He said more damage could be expected as the earthquake had been shallower and the fault-line had been much longer.
"The ground surface would have moved in the region of 4-5m (yards). So, you are talking very intense shaking over quite a large area. And that's why we'll probably see a significant impact from this event."
Thursday's magnitude-6.2 quake caused shaking at some places as intense as the huge earthquake that hit the country in 2011, Japan's seismology office said.
That quake sparked a huge tsunami and nuclear meltdown at The Fukushima power plant.
Most of those who died in Thursday's quake were in the town of Mashiki where an apartment building collapsed and many houses were damaged. More than 1,000 people were injured.
Some 40,000 people initially fled their homes, with many of those closest to the epicentre spending the night outside, as more than 130 aftershocks had hit the area.
