(NECN: Ally Donnelly) - The northeastern coast of Japan has been hit by a 7.1 magnitude earthquake -- a strong aftershock.
Thursday's quake hit 25 miles under the water and off the coast of Miyagi prefecture.
A tsunami warning was lifted 90 minutes after the quake hit.
Officials at the tsunami-ravaged Fukushima Dai-ichi nuclear plant said there's no immediate sign of new problems caused by the aftershock. 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 that preceded last month's tsunami was a 9.0 magnitude.
Last month's tsunami is believed to have killed some 25,000 people. Two Americans are confirmed dead.