Tokyo: At least 21 people were injured following a 6.7-magnitude earthquake that struck Japan's northwestern coast overnight and caused a slight tsunami, officials announced on Wednesday.
The quake occurred at 10.22 p.m. on Tuesday and had its epicentre at sea though near the coast close to the border that separates the prefectures of Niigata and Yamagata.
As soon as the seismic activity was registered, the Japanese Meteorological Agency (JMA) issued a tsunami alert that was lifted three hours later.
The tsunami's waves could be seen in Awashima, Sakata, Sado, Wajima and Niigata, where they reached a maximum height of 0.1 metres (less than four inches), according to the media agency's data.
Japanese authorities were still checking the state of buildings, although no serious structural damage to residences or installations has so far been identified.