A 7.4-magnitude earthquake has struck near Kumamoto in southern Japan.
Japanese broadcaster NHK said a number of calls were coming in from residents reporting people being trapped inside houses and buildings.
The quake hit at a depth of 40km (25 miles). The scientific agency earlier reported a 7.1 quake with a depth of 7km near the same location.
The Japan Meteorological Agency issued a tsunami advisory, urging people to leave coastal regions but it was lifted 50 minutes earlier.
There are fears that some people may be trapped in collapsed buildings and rescue services are working through the night.
Rescue teams fear more people are trapped under buildings after two major quakes in Japan.
More than 40 people are feared to have died after a powerful earthquake struck southern Japan on Saturday, the second quake in days.
More people have died in the latest powerful earthquake to hit Japan, just a day after a quake killed nine people in the same region.