Minor tsunami hit the northern Japanese coastline early Saturday, including in a city near the Fukushima nuclear plant, reports Japan Times. 

It was caused by a strong 6.8-magnitude earthquake struck off the Pacific coast.There were no immediate reports of damage, however, and authorities lifted all advisories roughly two hours later.

The manager of the Fukushima No. 1 nuclear plant said no abnormal activity was reported after the quake, which a Meteorological Agency official said appeared to be an aftershock of the Great East Japan Earthquake on March 11, 2011.

According to the United States Geological Survey, the quake struck around 129 km  east southeast of Namie, Fukushima Prefecture, at 4.22 a.m.

Minor tsunami as high as 20 cm were observed in Ishinomaki, Miyagi Prefecture, and Ofunato, Iwate Prefecture, the Meteorological Agency said.

At least three people were injured by the quake in Fukushima, said the Japanese public broadcaster NHK, including a 68-year-old woman who suffered a broken leg.