Tokyo,  An earthquake measuring 5.1 on the Richter scale struck off Japan's Fukushima prefecture on Friday, the national weather agency said, although no tsunami warning was issued.

According to the Japan Meteorological Agency (JMA), the temblor, which occurred at 3.19 p.m. (local time), was centred offshore with its epicentre at a latitude of 37.4 degrees north and a longitude of 141.3 east, reports Xinhua news agency.

The JMA also said the quake occurred at a depth of 30 km.

The earthquake logged lower 5 on the Japanese seismic intensity scale which peaks at 7 in some areas of Fukushima, according to the weather agency.

There have been no immediate reports of major damage or injuries as a result of the quake.

Japan's nuclear watchdog has not reported any abnormalities at any nuclear power stations, including the tsunami-stricken Daiichi nuclear power plant in Fukushima.