An earthquake struck northeastern Japan on Saturday, hitting areas devastated by the 2011 disaster, generating a tsunami of 1 metre and shaking buildings.

The quake, with a magnitude of 7.2, hit the coast of Miyagi Prefecture at 6:26 p.m. at a depth of 60 km (40 miles), the Japan Meteorological Agency said.

All tsunami alerts were lifted about an hour later, broadcaster NHK said after warning the public not to go near the shore. There were no immediate reports of deaths or injuries.

Tokyo Electric Power said it had found no irregularities at its Fukushima Daiichi nuclear plant - wrecked by the massive March 2011 quake that caused nuclear meltdowns and mass evacuations. A spokesman said there were also no irregularities at its nearby Daini facility.

Service on the Tohoku shinkansen bullet train was halted, NHK said and about 200 households in Kurihara city lost power because of the quake, the trade and industry ministry said.

The quake could be felt in Tokyo, about 400 km (250 miles) south of the epicentre.