TOKYO (AFP) -- A strong 6.4-magnitude earthquake hit northern Japan Saturday, but there were no reports of damage and no danger of a major tsunami, geologists said.

The quake struck at 1:34 p.m. (0434 GMT) off the Pacific coast of Miyagi prefecture, around the same area as the giant March 11 earthquake and tsunami, the United States Geological Survey said.

The Japan Meteorological Agency estimated the magnitude at 6.5.

The epicenter was 77 miles northeast of Sendai city, Miyagi's capital, the USGS said, estimating its depth at about 22 miles.

The quake didn't cause fresh damage to the crippled Fukushima Daiichi nuclear plant, according to its operator Tokyo Electric Power.

There were no immediate reports of damage or injuries, while the Pacific Tsunami Warning Center said there was "no destructive widespread tsunami threat" although a local tsunami could result from a quake of this size.

The Tohoku Shinkansen bullet train services were halted because of the quake, but resumed shortly afterwards.

The devastating March 11 twin disasters left about 22,000 people dead or missing and triggered an atomic crisis at the Fukushima plant, where emergency workers are still working to cool down the overheating reactor