A small tsunami hit the northeastern coast of Japan after a strong earthquakes overnight, but caused no apparent damage or injury in the same region hit by last year's devastating tsunami.
The first tremor off Hokkaido island was 6.8 magnitude and prompted some communities to issue evacuation orders or advisories to residents nearest the coast.
A 20 centimetre wave prompted authorities to issue an evacuation warning for coastal residents off the northern island of Hokkaido, but the tsunami advisories were lifted about 90 minutes later.
Smaller waves were also reported in several locations on Hokkaido island and Aomori prefecture.
The earthquake felt in Tokyo was magnitude 6.1 and centred just off the coast of Chiba, east of Tokyo, at a rather shallow 10 kilometres below the sea surface.
The town of Otsuchi in Iwate prefecture, where more than 800 died in last year's tsunami, issued an evacuation order to coastal households as a precaution after Wednesday's first quake, said prefectural disaster management official Shinichi Motoyama. No damage or injury was reported, he said.
Iwate was heavily damaged by last year's earthquake and tsunami. Thousands of aftershocks have shaken the region since then, nearly all of them of minor or moderate strength.
The magnitude 9.0 earthquake and tsunami on March 11, 2011 left some 19,000 people dead or missing.
Japan marked the first anniversary of the disasters on Sunday, as the country still struggled to rebuild.