The March 11 tsunami swept away or flooded more than 100 evacuation spots designated by local governments in north-eastern Japan, a news report said Wednesday, DPA reported.
Many people are believed to have died after fleeing to places supposed to be safe areas, Kyodo News agency reported.
No specific information has been collected so far on the number of deaths that resulted.
The tsunami hit at least 101 evacuation sites in the prefectures of Iwate, Miyagi and Fukushima.
In Minamisanriku City, Miyagi prefecture, for instance, 31 of its 80 designated sites were hit. "Most of them were washed away," an unnamed official was quoted as saying.
Onagawa Town's 25 sites had been set up at locations at least six metres above sea level in response to the tsunami that reached the region after the 1960 Chile earthquake. But the March tsunami hit 12 of the 25 sites.
There have been no attempts to date by citizens to hold the authorities responsible for designating those areas, apparently because the tsunami's size was unexpected.