TOKYO ? A strong, 6.6 magnitude earthquake hit northern Japan Sunday afternoon, said the Japanese government, which did not issue a tsunami warning.

The quake happened at 5:08 pm (0808 GMT) off the Pacific coast of Fukushima prefecture, the Japanese Meteorological Agency said.

"It is possible that the tidal level would change slightly. But there is no worry about damage," the agency said.

Some train services automatically stopped immediately after the quake, before resuming normal operations.