Tokyo. A tsunami warning has been issued for the northeastern Pacific coast after a 6.7-magnitude earthquake struck off the coast of Japan on Sunday evening.

According to the Japan Meteorological Agency (JMA), the quake struck at 5:03 p.m. (0803 GMT) off the coast of Iwate Prefecture. The agency issued a possible tsunami warning of up to one meter (three feet) in height, urging coastal residents to remain vigilant.

The United States Geological Survey put the magnitude of the quake at 6.8 on the Richter scale. The JMA said a “tsunami advisory” had been issued for the Iwate coast and warned that waves could reach the coast at any time. Meanwhile, national broadcaster NHK confirmed that small tsunami waves had been spotted offshore and urged the public to stay away from the beach and move to higher ground.

Japanese television broadcast live showed that the seas appeared relatively calm, but authorities urged caution. The region is haunted by painful memories of the devastating 9.0-magnitude undersea earthquake of 2011. The earthquake triggered a huge tsunami. About 18,500 people died or went missing.

The tsunami caused the melting of three reactors at the Fukushima nuclear power plant, causing the biggest disaster in Japan’s history and the world’s second-largest nuclear accident after Chernobyl.

Japan is located on the western edge of the Pacific Ocean called the ‘Ring of Fire’, where four major tectonic plates collide. Japan is one of the most seismically active countries in the world.

With a population of about 125 million, the archipelago experiences more than 1,500 earthquakes every year. Although most of them are mild in nature, their level of damage depends on the depth of the earthquake and the settlements near the epicenter.