A powerful earthquake rattled northern Japan early Thursday, injuring at least 99 people, triggering landslides and cutting power to thousands of households. Japan's Meteorological Agency said the temblor, which had a preliminary magnitude of 6.8, struck shortly after midnight at a depth of about 105 kilometers near the coast of Iwate, 450 kilometers northeast of Tokyo. Most of the injuries were cuts and bruises from broken glass and falling objects. None were life threatening, said a National Police Agency official on condition of anonymity, citing department policy. The earthquake caused strong shaking of up to 40 seconds in many areas of northern Japan, witnesses said.