A 5.5-magnitude earthquake struck off the east coast of Japan on Monday, the U.S. Geological Survey reported, but no tsunami warning was issued.
The quake hit at a depth of 26 kilometers at 3:13 a.m., about 324 kilometers east of the town of Namie, Fukushima Prefecture,the USGS said.
The Pacific Tsunami Warning Center did not issue an alert.
A powerful 7.1-magnitude undersea quake off the east coast two days ago triggered a small tsunami, which was recorded as being as high as 55 centimeters in one place.
Workers were evacuated from the crippled Fukushima nuclear plant on Saturday but there were no reports of any damage. Japan's meteorological agency said the quake was an aftershock of the disastrous March 2011 tremor.© (c) 2013 AFP