TOKYO -- At least 19 houses collapsed after an earthquake struck southern Japan late Thursday, the country's National Police Agency said.
An unknown number of people were still trapped under collapsed buildings Thursday night, Chief Cabinet Secretary Yoshihide Suga said.
The U.S. Geological Survey said the magnitude-6.2 quake struck near Ueki, Japan. Several smaller aftershocks occurred shortly afterward.
The National Police Agency reported 12 injuries. Several fires also broke out in the town of Mashiki, Japanese broadcaster NHK said.
Gen Aoki, director of the Japan Meteorological Agency's earthquake division, warned that more aftershocks could occur over the next week.
"This is an earthquake that is going to shake for a long time," CNN meteorologist Chad Myers said.
An estimated 750,000 people felt the shaking Thursday, Myers said.
"The strongest shaking was right where the most people live" in the area, he said.
While the magnitude might not seem extreme, the shallow depth of the quake -- just 10 kilometers (6.2 miles) -- probably means significant damage.
"When you have a shallow earthquake, you have the potential for more damage," said John Bellini of the U.S. Geological Survey.
In addition to destroying 19 houses, the quake hurled items off store shelves and littered streets with rubble.