At least 15 people have died in the latest powerful earthquake to hit Japan, just a day after a quake killed nine people in the same region.
The magnitude 7.3 earthquake struck southern Japan bringing down buildings and causing a huge landslide in Kumamoto Prefecture.
The authorities warned of damage over a wide area, as reports came in of scores of people trapped in collapsed buildings, fires and power outages.
Residents living near the Nishihara Ookiribata dam were told to leave because of fears it might crumble, broadcaster NHK said.
A fire erupted in a what appeared to be an apartmentbuilding in Yatsushiro city, while some people were trapped in a nursing home in the town of Mashiki, according to NHK.
NHK reported three deaths and nearly 400 people treated in hospitals, but that figure included "people who don't feel well," so it was not clear how many serious injuries there were.
Chief Cabinet Secretary Yoshihide Suga said nearly 80 people were believed trapped or buried in rubble.
Extra troops would be sent to help, with up to 15,000 due on Saturday, as well as more police, firefighters and medics, he said.