A strong earthquake of magnitude 5.9 shook northeastern Japan on Friday, followed by at least three large aftershocks, but there was no danger of a tsunami, the Meteorological Agency said. The quake struck at 1:37 p.m. (0437 GMT), centered about 30 kilometers (20 miles) below the seabed in the Pacific Ocean just off the coast of Ibaraki prefecture (state), the agency said.
It was followed by two magnitude 5.0 aftershocks, one at 2:38 p.m. (0538 GMT) and the other three minutes later at the same location, the agency said. A 5.3-magnitude aftershock followed at 3:10 p.m. (0610 GMT) at a slightly shallower depth, the agency said.
There were no immediate reports of injuries or damage from the quake, local police said. Ibaraki is about 130 kilometers (80 miles) northeast of Tokyo. The tremors also were felt in the northeastern prefectures (states) of Fukushima and Miyagi but hardly felt in Tokyo.
Japan sits atop four tectonic plates and is one of the world's most earthquake-prone countries, reports the AP.