Japan briefly issued a tsunami alert after a magnitude-6.7 earthquake struck in the northeast of the country, rattling the areas hardest hit by the March 11 quake and tsunami disasters.
The alert has since been lifted.
The meteorological agency said the latest jolt hit at 6:51 am (0951 NZT) some 50 kilometres off the east coast of Miyako, Iwate prefecture, at a depth of 20 kilometres in the Pacific.
The northeast coast of Japan's main Honshu island was ravaged by a 9.0 magnitude quake and monster tsunami on March 11 which left more 23,000 people dead or missing.
The disasters also crippled the Fukushima Daiichi nuclear power plant, triggering the world's worst atomic accident since Chernobyl in 1986 and forcing hundreds of thousands of residents to leave their homes.