At least 40 people were killed and several others injured or feared buried in the building collapses and landslides as 7.3 magnitude earthquake at the wee hours of Saturday morning shook Japan's Kumamoto on Kyushu island, just over a day after a quake killed nine others in the same region.
The 6.5 magnitude quake on Thursday in the same region of Kumamoto brought down buildings, killing nine people and injuring about 800.
Hundreds of aftershocks followed until the ultimately bigger quake on Saturday morning.
According to the United States Geological Survey, the epicenter of the quake was near the city of Kumamoto and measured at a shallow depth of 10 km.
The Japanese government's chief cabinet secretary, Yoshihide Suga, said that 1,500 people had been injured and 80 of them were seriously injured, reports the Japan times.
The authorities have warned of damage over a wide area as reports poured in scores of people trapped in collapsed buildings.
The powerful shake triggered a huge landslide that swept away homes and cut off a national highway in Minamiaso forcing people to battle for lives in the tragedy.
Tsunami warnings were triggered on Saturday adding atmosphere of confusion among the evacuees who had already witnessed their homes collapse before their eyes.
Japanese media reported that nearly 200,000 homes were without electricity.
Meanwhile, Suga informed media persons that rescue operations were underway and the efforts have been increased with troops in the area being raised to 20,000, while additional police and firefighters were also on the way.
He, however, warned that number of casualties might surge and pleaded people not to panic.
"Please let's help each other and stay calm," The Guardian quoted him as saying in a nationally televised news conference.
Prime Minister Shinzo Abe, said that his the government was making every effort to determine the extent of the damage, carry out rescue and recovery, and to get accurate information to citizens.
According to reports, the Japan Meteorological Agency has said that a small eruption at Mount Aso, an active volcano in Kumamoto prefecture, was unrelated to the quakes.
Japan is on the seismically active ‘ring of fire’ around the Pacific Ocean and because of thet its buildings are made to withstand earthquakes.
In 2011, a magnitude-9 quake in the Tohoku region touched off a massive tsunami and nuclear meltdowns at Fukushima killing nearly 20,000 people in the tsunami.