A powerful earthquake rocked northern Japan early this morning, generating a tsunami and temporarily affecting the Fukushima nuclear plant.

Powerful quake hits Fukushima, residents urged to flee

The earthquake, which was felt in Tokyo, had a preliminary magnitude of 7.4 and was centered off the coast of Fukushima prefecture at a depth of about 10 kilometers. Two injuries were reported.

A tsunami of up to 1 metre had been observed around Fukushima following the quake, after a warning of waves of up to 3 meters had been issued.

Japan's Chief Cabinet Secretary Yoshihide Suga said the cooling system at a reactor at the Fukushima Daiichi nuclear plant had been restarted after a temporary stoppage. He also urged residents who may be affected by the tsunami to evacuate to safer ground.