SOMA, JAPAN (AFP) – Four people were reported dead and over 100 injured in Japan after a powerful overnight earthquake rattled large parts of the east coast and prompted a tsunami warning, authorities said.

The 7.4-magnitude quake off the coast of Fukushima derailed a bullet train, opened cracks in highways and threw products from shelves in shops. A tsunami warning for waves of up to a metre in parts of northeast Japan was lifted in the early hours of yesterday, after authorities recorded water levels up to 30 centimetres higher than usual in some areas.

Multiple smaller jolts continued to hit the region into yesterday morning, straining nerves just days after Japan marked the 11th anniversary of the massive quake, tsunami and nuclear disaster in the area.

“This is really ironic. Exactly a year ago, we also had a similar-scale earthquake,” store employee Yoshinari Kiwaki told AFP.

“When we felt the tremor last night, we already knew what we would have to work on here in the morning,” the 62-year-old added, saying it would take around a month to get the store back in business.

The jolts also rattled the capital and temporarily plunged parts of Tokyo and other areas into darkness.

Four dead after powerful Japan quake rattles east coast

Blackouts hit around two million homes in Tokyo and elsewhere in the immediate aftermath of the quake, but power was progressively restored throughout the night. Some 30,000 homes were still without power yesterday morning, with another 4,300 without water.

Elsewhere, some damage was reported, including the collapse of a stone wall at the site of Aoba castle in Sendai, and a Shinkansen bullet train derailed north of Fukushima city.

There were no injuries in the derailment, but 75 passengers and three staff on board were trapped for four hours before being able to escape the train. Several dozen people were still at an evacuation centre in Soma, where 82-year-old Yuzuru Kobashi was collecting food and water.

Some of his roof slates fell off in the quake, but he told AFP he cannot climb up to fix emergency tarpaulin in place because of his age.

“So instead of using tarps to cover the roof, we are using them to cover important items in the house so they won’t get wet when it rains,” he said.

Japan sits on the Pacific “Ring of Fire”, an arc of intense seismic activity that stretches through Southeast Asia and across the Pacific basin.

The country is regularly hit by quakes, but it remains haunted by the memory of the 2011 catastrophe which left 18,500 people dead or missing, most in the tsunami.

Around the stricken Fukushima plant, extensive decontamination has been carried out, and no-go zones now cover just 2.4 per cent of the region, down from 12 per cent, though populations in many towns remain far lower than they were before.