TOKYO, April 18 (Xinhua) -- A 5.0-magnitude earthquake struck Nagano Prefecture in central Japan on Saturday, the country's weather agency said.

The temblor occurred at 1:20 p.m. local time at a depth of 10 km, measuring upper 5 on Japan's seismic scale of 7 in the hardest-hit areas, said the Japan Meteorological Agency (JMA).

The quake's epicenter was located in northern Nagano Prefecture at a latitude of 36.6 degrees north and a longitude of 137.9 degrees east.

No immediate injuries or damage have been reported so far. ■