Originally published April 7, 2011 at 8:30 a.m., updated April 7, 2011 at 10:02 a.m.
Japan was hit by a strong earthquake and tsunami warning Thursday night nearly a month after a devastating temblor and tsunami flattened the northeastern coast.
Japan's meteorological agency issued a tsunami warning but lifted all alerts less than two hours later. The warning had been issued for a coastal area torn apart by the twin disasters March 11 that killed thousands of people and sparked an ongoing crisis at a nuclear power plant.
Thursday's earthquake had a preliminary magnitude of at least 7.1, according to the U.S. Geological Survey. It hit off the coast of Miyagi prefecture at a depth of about 30 miles. The quake that preceded last month's tsunami was a 9.0-magnitude.
Officials at the tsunami-ravaged Fukushima Dai-ichi nuclear complex said there was no immediate sign of new problems caused by the latest earthquake. Japan's nuclear safety agency said workers there had retreated to a quake-resistant shelter in the complex. Plant operator Tokyo Electric Power Co. said it evacuated two workers there and seven at a sister plant to the south that was not badly damaged.
The quake struck at 11:32 p.m. local time. Japanese TV flashed a warning about an impending quake moments before it struck. In Tokyo's western suburbs, loudspeakers warned residents.
Parts of Tokyo "shook for about two minutes," NPR's Greg Dixon reported, even though the quake epicenter was more than 200 miles away. He said there were no immediate reports of damage.
In Ichinoseki, inland from Japan's eastern coast, buildings shook violently, knocking items from shelves and toppling furniture, but there was no heavy damage to the buildings themselves. Immediately after the quake, all power was cut. The city went dark, but cars drove around normally and people assembled in the streets despite the late hour.
NPR's John Burnett said he was in bed on the 32nd floor of a hotel in Sendai, about 40 miles from the epicenter, when the building began to shake.
"It started shaking back and forth tremendously, and the hangers in the closet made quite a racket and then the hotel alarm system went on," Burnett said. "We heard the voice of someone on the PA saying that the elevators were down."
NHK also was reporting that the earthquake hit the Tohoku region in northern Japan — the same region that was devastated by the March earthquake and tsunami. Hundreds of aftershocks have shaken the northeast region since last month's temblor, but few have been stronger than 7.0.
With reporting from NPR's Greg Dixon in Tokyo and John Burnett in Sendai, Japan. Material from The Associated Press was used in this story.