An earthquake measuring 6 on the Richter scale on Sunday hit the northeastern Japanese coastal region, but no tsunami alert was issued and no serious damage was registered in the areas close to the epicenter, the Japanese Meteorological Agency reported.

The quake struck at 12:29 p.m. (0329 GMT) and was located some 50 kilometers below the surface of the ocean, very near the city of Ishinomaki in Miyagi prefecture, one of the regions hardest hit by the powerful quake and tsunami that devastated the northeastern part of the country on March 11, 2011.

Tokyo Electric Power (TEPCO) said that no anomalies had been detected at its Fukushima Daiichi nuclear power plant, which in 2011 was the site of the worst nuclear crisis since Chernobyl, adding that no problems were noted at the Fukushima Daini power plant either.

Tohoku Electric Power also said that no damage had occurred at its Onagawa nuclear plant, the one closest to the temblor's epicenter.

As a result of the quake, the Tohoku bullet train line was halted for several minutes but resumed normal operations later, NHK public television reported.

One stretch of the highway between the Miyagi capital of Sendai and the Pacific coast was closed temporarily as a precaution.

Authorities at the Sendai airport did not report any serious damage.

The quake was felt - by instruments at least - in 19 of the country's 47 prefectures, including Tokyo.

Japan sits on the so-called "Pacific Ring of Fire" and experiences relatively frequent earthquakes, a situation that has caused authorities to implement very strict construction regulations and develop rigorous emergency plans. EFE