A strong earthquake struck eastern areas of Hokkaido Prefecture on Saturday, prompting authorities to urge vigilance.
The quake, with a magnitude of 5.8, had a seismic intensity of lower 5 in the city of Nemuro, the fifth-highest level on the Japanese scale.
The agency called on people to remain alert for more temblors measuring up to a lower 5 for about a week.
The earthquake occurred at the boundary of two plates, where an ocean plate is subducting beneath a land plate, off the southeastern coast of Hokkaido.
Author's summary: Strong quake hits Hokkaido, authorities warn of more temblors.