Authorities had issued evacuation orders in some parts of the devastated coastline after the initial report and seawater was seen retreating off Iwate and Aomori prefectures a phenomenon that occurs before tsunamis.

Public broadcaster NHK had reported that the crew of a fire department helicopter had spotted a three metre or 10 foot high tsunami off Fukushima prefecture, saying it was expected to hit shortly after 0230 GMNT.