At least three people died and dozens more are trapped or buried under rubble after a magnitude-7.3 earthquake struck the southern Japanese island of Kyushu early Saturday, authorities said.
The quake, upgraded from a preliminary magnitude of 7.0, hit one day after nine people were killed and 1,100 injured in a magnitude-6.5 earthquake in the same region - the strongest in five years.
Saturday’s quake occurred at 1:25 am (1625 GMT) with its epicentre in the Kumamoto region at a depth of 12 kilometres, the Meteorological Agency said.
Chief Cabinet Secretary Yoshihide Suga told a news conference that significant damage was feared from the fresh quakes and the government was to dispatch 20,000 troops to the affected region.
Suga said there were no abnormalities at nearby nuclear power stations.
More than 200,000 household lost electricity in three prefectures on the island, Kyodo News agency reported.
Japan is one of the most earthquake-prone countries in the world. Strict building regulations mean that damage to infrastructure is often minimal even after strong earthquakes.