At least 15 people were killed and 760 injured as a powerful earthquake measuring 7.3 on the Richter Scale hit Japan's Kumamoto prefecture on Saturday.
Quake came close on the heels of tremors felt on Thursday that killed nine people, 'The Japan Times' reported.
Officials reported of damage over a wide area, as reports came in of scores of people trapped in collapsed buildings, fires and power outages.
There were also report of "small-scale" eruption at Mount Aso, a large active volcano in Kumamoto, in media. The Japanese Meteorological Agency said it was not clear how the eruption was linked to the quakes.
Heavy rain prediction for the coming days could cause more landslides and affect already damaged structures, the meteorological agency said.
Kumamoto prefecture police said they have received reports of 97 people trapped or buried under collapsed buildings.
Saturday's temblor triggered a tsunami advisory, although it was later lifted and no irregularities were reported at three nuclear power plants in the area, a senior government official said.
People still reeling from Thursday's shock poured onto the streets as the quake struck around 1.25 a.m. (local time) on Saturday.