Japan has been shaken by a strong earthquake off its eastern coast, closer to Tokyo than the massive quake that hit Friday.
The latest temblor swayed buildings in the capital.
The US Geological Survey says the temblor had a magnitude of 6.2 and struck on Sunday.
It was centered about 179 kilometres east of Tokyo, at a depth of 24.5 kilometres.
Japan's northeastern coast was battered on Friday by a magnitude 8.9 quake, the largest on record in Japan, and an ensuing tsunami that washed over hundreds of kilometres of coastline, causing widespread destruction.
Japan has been rattled by more than 150 aftershocks since Friday's massive quake.