Anearthquake measuring 7.2 on the Richter scale struck north-eastern Japan on Saturday,prompting authorities to issue a tsunami warning for Miyagi prefecture.
TheJapan Meteorological Agency warned of up to a 1-metre high tsunami in Miyagiand the first tsunami wave has already swept ashore in the city of Ishinomaki,dpa news agency quoted the national broadcaster NHK as saying.
Thewarning prompted some residents in Miyagi to rush to higher ground ahead of thepossible arrival of tsunami, NHK footage showed.
Therewere no immediate reports of casualties or damage to property. The quake alsoshook buildings in Tokyo.
Thetemblor occurred at 6.09 p.m. (local time), with its epicentre located at alatitude of 38.4 degrees north and a longitude of 141.7 degrees east, and atthe depth of 60 km, the agency said.
OnMarch 11, Japan marked the 10th anniversary of a magnitude-9.0 quake andresulting tsunami that struck the same region in 2011, leaving about 18,400dead or missing.
Thetwin natural disasters caused a triple meltdown at the Fukushima DaiichiNuclear Power Station, which spewed radioactive substances into theenvironment.
Thenuclear emergency prompted hundreds of thousands of residents to flee theirhomes. A month ago, a magnitude-7.3 quake also rocked the north-east, killingone person and injuring about 190 others.
Japansits at the convergence of four tectonic plates, making it especially prone toseismic activity. The country is also home to 100 active volcanoes.