There were no immediate reports of damage from the 4.24am (local time) earthquake, which had an epicentre 30km under the seafloor off Fukushima. No tsunami warning was issued.

Fukushima was jolted on March 11 by a magnitude-9 quake, which caused major damage across the region and set off a tsunami that devastated coastal communities. The twin disasters damaged a powerplant, leading to a nuclear meltdown.

Tokyo Electric Power Company, operator of the Fukushima Daiichi nuclear plant, reported no immediate problems on November 24 at the crippled facility, broadcaster NHK said.

The latest earthquake was strong enough to set skyscrapers swaying in Tokyo, 260km away.