A massive earthquake of magnitude 7.4 struck Japan, off the northeastern coast, on Monday. A tsunami alert has been issued after the quake, according to the Japan Meteorological Agency.The earthquake struck at 4.53 pm local time (0753 GMT) in the Pacific Ocean off northern Iwate Prefecture at a depth of 10km deep. The tremors were powerful enough to sway high-rise buildings as far away as Tokyo, several hundred kilometres from the epicentre.The powerful seismic activity further It also issued a warning for tsunami waves of up to 3 meters (10 feet) height in Iwate prefecture and parts of Hokkaido, as reported by Reuters, quoting the Japanese agency.The weather agency warned that the earliest tsunami waves could reach the northern coastline almost immediately. “Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building,” it said, cautioning that damage from tsunami waves was likely. “Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted,” it added.