A 5.8-magnitude jolt struck off the coast of the northeastern Fukushima region, home to the plant wrecked by a tsunami in 2011, at 00:14 am Friday (1514 GMT Thursday), the Japan Meteorological Agency said.

"We have confirmed remotely that there were no abnormalities on ALPS treated water dilution/discharge facility, etc.," Tokyo Electric Power Company (TEPCO) said on X, formerly Twitter, referring to the water release process.

But "to be on the safe side, we have suspended the operations of the facilities in accordance with the pre-defined operational procedures", it said in the early hours of Friday.

Several hours later TEPCO said in a statement that "no abnormalities were detected" and a spokesman told AFP that the water release would resume later on Friday.

No leak of radiation was detected after TEPCO finished necessary checks while "readings from monitoring posts remain normal", he added.

Japan's nuclear regulatory authority also said shortly after the quake that no abnormalities were detected at either the wrecked Fukushima Daiichi plant, or its sister plant Fukushima Daini.

Last August, TEPCO began releasing into the Pacific Ocean around 540 Olympic swimming pools' worth of wastewater that has collected at Fukushima Daiichi since the 2011 accident, one of the world's worst nuclear disasters.

The operation has been endorsed by the UN atomic agency, and TEPCO says all radioactive elements have been filtered out except for tritium, levels of which are within safe limits.

But China and Russia have criticised the release into the Pacific and banned Japanese seafood imports, saying that Japan is polluting the environment.

Japan experiences hundreds of earthquakes every year and the vast majority cause no damage.

There were no immediate reports of injuries from the latest jolt and there was no tsunami warning.