Earthquakes with a magnitude of between five and ten have hit Japan twelve times in the last three days and killed at least 34, according to the US Geological Survey.
The quake with the highest magnitude in the last three days has been 7.0, which hit southern Japan on April 15.
Scores of people were feared to be buried alive after the earthquake, killing at least 25, and sparking collapses and fires.
At least 1,500 have been wounded with thousands more evacuated while rescue workers search through debris.
On April 14 a magnitude 6.2 earthquake struck Japan 7 km (4.3 mi) southwest of Ueki, Kumamoto Prefecture and in the same day another earthquake with a magnitude of 6.0 also hit Japan 5 km (3.1 mi) east of Uto, Kumamoto Prefecture, leaving nine people dead.
More than 140 aftershocks were registered within two days.
The quakes brought down some buildings but the nuclear regulator reported no problems at power plants.
There were no tsunami warnings after the earthquakes erupted between April 14 and 16.
All of them had taken place in southern Japan.
A magnitude 9 quake on March 2011, to the north of Tokyo, triggered a massive tsunami and nuclear meltdowns at Fukushima. Nearly 20,000 people were killed in the tsunami.
Japan is an area of high seismic movement due to its close location to three major tectonic plate boundaries. It is settled in a volcanic zone on the Pacific Ring of Fire where a great number of earthquakes and volcanic activities take place.