A tsunami measuring one metre (3.3 feet) hit Japan's coast at the stricken Fukushima nuclear plant on Tuesday following an earthquake, operator Tokyo Electric Power said.

The tsunami struck at 6:38 am (2138 GMT), a TEPCO official told a televised news conference after a magnitude 6.9 earthquake hit the region earlier.

A but TEPCO spokesman told AFP that there were no reports of any problems as a result of the wave.