A small tsunami hit Japan after the 6.8 Earthquake

A small tsunami wave struck Japan's northeastern shoreline on Wednesday, officials said, after having a strong quake rocked the vicinity a year on from the country's toughest post-war natural devastation.

The 20 centimetre (eight inch) wave and 6.8-magnitude quake, which struck around 210 kilometres (130 miles) off the northern island of Hokkaido, prompted local authorities to issue an evacuation warning for coastal residents before it hit land.

Japan's meteorological agency also confirmed that an earlier 10-centimetre wave hit land.

The waves hit two locations in Aomori prefecture, which was one of the areas in Japan's northeast devastated by last year's disaster.

The agency had initially said a tsunami could be as high as 50 centimetres, but U.S. monitors said there was no Pacific-wide tsunami threat.

The quake struck at a relatively shallow 10 kilometres below the seabed at 6:09 p.m. local time.