A strong quake with a preliminary magnitude of 6.3 jolted northeastern parts of Japan at 2:07 p.m. local time (0507 GMT), according to Japan Meteorological Agency.

Severe tremors were felt in Fukushima and Ibaraki prefectures. The epicenter was located in the Hamadori area of Fukushima.

Workers at the crippled Fukushima No. 1 nuclear power plant were ordered to evacuate, according to the operator of the plant Tokyo Electric Power Co. The order was later lifted because no abnormalities had been found at the plant's reactors.

A series of aftershocks have been occurring following the catastrophic earthquake and tsunami.

On Tuesday morning, an earthquake with a preliminary magnitude of 6.3 jolted Chiba Prefecture, east of Tokyo, and neighboring areas at 8:08 a.m. local time, according to the Japan Meteorological Agency. No tsunami warning was issued after the quake.