A powerful 7.0 magnitude earthquake hit southern Japan early Saturday, the U.S. Geological Survey said, a day after another powerful tremor killed at least nine people in the same area.
The quake hit Kumamoto prefecture of the Kyushu main island at 1:25 a.m., the USGS said.
The Japan Meteorological Agency, which put the magnitude at 7.1, initially issued a tsunami warning for the western coast of Kyushu island, where hundreds were injured in a quake late Thursday, but later lifted it.
Several aftershocks rattled the area after Saturday's earthquake, the Japanese Meteorological Agency said.
NHK said there were multiple reports of fresh injuries and that a bridge in Kumamoto city had collapsed, though that could not be immediately confirmed.
There were several reports of people being trapped under debris at various locations, and the broadcaster showed images of rescue workers removing debris from atop a collapsed house in an apparent search for anyone trapped underneath.
Other footage showed residents gathering in a park and also scenes from the NHK bureau in Kumamoto city immediately after the quake, with objects falling off desks and shelves.
A 6.5-magnitude quake that struck late Thursday killed nine people and injured nearly 900.
According to the USGS, aftershocks are smaller earthquakes that occur after a larger event, the mainshock. If an aftershock occurs that's larger than the earlier quake, the larger earthquake is considered the mainshock -- and the earlier quakes are called foreshocks.