A magnitude-7.3 earthquake has struck the southern Japanese island of Kyushu, bringing down buildings, killing at least 22 people and injuring many more. Saturday morning's quake hit just one day after an earlier large tremor that killed nine people.

The quake occurred at 01:25 AM local time, with an epicenter near the city of Kumamoto, and at a shallow depth of 10 kilometers. The tremor was felt across wide swathes of southern Japan. Authorities warned of the rise in death toll, as reports came in of scores of people trapped in collapsed buildings.

No irregularities have been reported at three nuclear power plants in the area. Japan weather authority said rain is expected on Saturday night and more aftershocks are possible. They warned of secondary disasters, including landslides and the collapse of houses. 

Japanese broadcaster NHK interrupted their programming to announce the quake....

The quake left dozens of houses collapsed, and some 200 thousand households experienced power failure. 

Frightened locals stayed in the open air for fear of further aftershocks.

"I am so shocked. I cannot even sleep after the earthquake," said a quake victim.

"The aftershocks are continuing so I cannot even begin to think of what's ahead," said another quake victim.

The transportation network was stunted, with roads blocked by landslides, and railway and air services suspended.

A small eruption occurred at Mount Aso in southern Japan, with smoke rising about 100 metres high.

Japanese Prime Minister Shinzo Abe ordered more troops to mobilize to quake-hit region.

"I order to reinforce a great number of Self-Defence Force troops and other disaster relief officials to the earthquake-hit area to concentrate the government's full capacity on the rescue, evacuation and life-saving operations," he said.

Abe said the damage from the quake would possibly "spread widely" and urged rescue workers to do their utmost to help those trapped in the rubble.