Thousands seek refuge after quake in Japan

On Genkaijima, a small island off the northern coast of Kyushu and hardest hit by the quake, about 200 buildings were either destroyed or damaged, and roads were cracked and blocked in many areas by debris.

Most of the 700 residents of the hilly island fled to the main island and spent a sleepless night in gymnasiums used as evacuation centers.

"I could not sleep because I was so worried," said one Genkaijima resident, a man in his 40s.

"I wanted to stay on the island, but the aftershocks were getting so bad, I felt it was just too dangerous," he said, sitting up on his futon mattress.

The focus of Sunday's quake was shallow and off the western coast of Fukuoka Prefecture, about 900 km (550 miles) southwest of Tokyo.

Soldiers in camouflage fatigues carried out relief operations on Genkaijima while police and government officials wearing helmets toured the island to assess the damage.