Powerfull quakes have been registered in Japan and Indonesia on Sunday.

A strong, 6.6 magnitude earthquake hit northern Japan but no tsunami warning was issued, US and Japanese authorities said.

The quake struck at 5:08 pm (0808 GMT) in the Pacific off Fukushima prefecture, 250 kilometres north of Tokyo, the US Geological Survey (USGS) and the Japanese Meteorological Agency said in separate statements.

"It is possible that the tidal level would change slightly. But there is no worry about damage," the Japanese agency said.

There were no immediate reports of casualties or damage.

The quake was strong enough to sway skyscrapers in Tokyo, where national television networks had issued flash warnings of a possible large quake before the tremors could be felt in the capital.

Some train services in the region, including the Shinkansen bullet trains, stopped immediately after the quake, but gradually resumed normal operations.

A 7.0-magnitude quake hit off the eastern Indonesian island of Maluku on Sunday, seismologists said, but no tsunami warning was issued.

The quake struck at 07:47 pm local time (1247 GMT) about 132 kilometres southeast of Labuha, North Maluku province, at a depth of 56 kilometres, the Indonesian Meteorology and Geophysics Agency said.

"There has been no report of casualties so far. There was some shaking felt in several areas but it's not strong," the agency's technical chief Suharjono told AFP.

Indonesia sits on the Pacific "Ring of Fire," where the meeting of continental plates causes high volcanic and seismic activity.