Buildings, even in far away Tokyo, shook vigorously and live footage by public broadcaster NHK showed a wide, muddy stream moving rapidly across a residential area near Natori River in Miyagi, levelling everything in its path.
The 33-foot tsunami, triggered by an 8.9-magnitude quake, struck at 2:46 pm local time (11:16 am IST), and was one of the strongest to have hit the quake-prone region, according to the Japan Meteorological Agency.
Its magnitude surpassed the earthquake of 7.9 on Richter scale registered in Great Kanto area in Tokyo and its vicinity in 1923, which had killed more than 140,000 people, Kyodo news agency reported.
The quake, which sparked fires in several areas including Tokyo, struck about 400km from the capital and there have also been powerful aftershocks. Tsunami waves hit Japan's Miyagi and Fukushima prefectures, officials said, adding the quake caused "tremendous damage".
Nuclear plants on the Pacific Coast in Miyagi and Fukushima prefectures shut down automatically following the quake, the operator Tokyo Electric Power Co. was quoted as saying by Kyodo. The tsunami also reached Sendai airport submerging the runway.
Prime Minister Naoto Kan said the quake caused "major damage in broad areas" but nuclear power plants in the area were not affected. Authorities prepared to send troops to the quake-hit areas. Media reports said that at least 26 people were killed.
US Ambassador to Japan John Roos said that US forces stationed in the country were ready to work with authorities to help them cope with the massive earthquake.
"I want to have the Defence Ministry and the Self-Defense Forces work with the US military if necessary," Japanese Defence Minister Toshimi Kitazawa was quoted as saying at the outset of an emergency meeting held at the ministry.