A tsunami alert for the coastal region of north-eastern Japan has been lifted following an earthquake of magnitude of 7.1.
Workers at the Fukushima Daiichi nuclear plant, devastated in last month’s quake and tsunami, were evacuated.
But officials at the plant said there was no detectable effect there or at other nuclear plants in the region.
The Japanese authorities ordered a general evacuation from the warning zone.
Japan meteorological agency had earlier issued a warning for a wave of up to two metres in a coastal area devastated by last month’s tsunami.
“Based on all available data, a destructive Pacific-wide tsunami is not expected,” the Pacific Tsunami Warning Centre said on its website.
But it warned: “Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within 100km of the earthquake epicentre.”
There was no threat to Hawaii, it added.
The quake struck at 2332 local time (1432 GMT) on Thursday, 118km (78 miles) north of Fukushima, 40km offshore.
It struck at a depth of 49km. Last month’s earthquake had a magnitude of 9.0 and struck at 32km deep.
Efforts to cool down three of the reactors at the Fukushima Daiichi plant are continuing in a stable manner, reports Japanese TV station NHK.