* Quake has preliminary magnitude of 7.2 - agency
* Tsunami advisory up to 50 cm issued for northeastern Japan
* No impact on nuclear plants (Adds details, quote)
TOKYO, March 9 (Reuters) - A strong earthquake with a preliminary magnitude of 7.2 hit off the coast of northeastern Japan on Wednesday, the Japanese Meteorological Agency (JMA) said, but there were so far no reports of damage from the quake.
A tsunami advisory of up to 50 cm (about 20 inches) was issued for northeastern Japan after the quake hit around 11:45 a.m. (0245 GMT), JMA said.
“First I felt a jolt that pushed from underneath, then a big sideways tremor that lasted for about 20 seconds,” Yoshiyuki Sato, an official at Kurihara City in Miyagi prefecture, about 300 km (186 miles) northeast of Tokyo, told Reuters.
“The tremor was relatively big but things did not fall off the shelves in the city government building,” he said.
The focus of the tremor was 10 km (6 miles) below the surface of the earth, off the coast of Aomori prefecture, public broadcaster NHK said.
An official at the National Police Agency said there was no information on damage from the quake so far.
Bullet trains resumed running in northeastern Japan after stopping briefly, Kyodo news agency reported.
Earthquakes are common in Japan, one of the world’s most seismically active areas. The country accounts for about 20 percent of the world’s earthquakes of magnitude 6 or greater. (Reporting by Yoko Kubota, Shinichi Saoshiro and Kiyoshi Takenaka; Editing by Nathan Layne and Chris Gallagher)