Magnitude 7.2 earthquake strikes off Japan's northern coast and triggers tsunami alert

A powerful 7.6-magnitude earthquake struck off northern Japan late on Monday, triggering a tsunami of up to 70 centimetres in Pacific coast communities and warnings of potentially higher surges, the Japanese Meteorological Agency said.

Several people were injured, media reports said.

The quake struck at about 11:15 pm in the Pacific Ocean about 80 kilometres off the coast of Aomori, the northernmost prefecture of Japan's main Honshu island, the agency said.

A tsunami of 70 centimetres was measured in Kuji port in Iwate prefecture, just south of Aomori, and tsunami levels of up to 50 centimetres struck other coastal communities in the region, the agency said.

The agency issued an alert for potential tsunami surges of up to three metres in some areas, and Chief Cabinet Secretary Minoru Kihara urged residents to immediately head to higher ground or take shelter inside buildings or evacuation centres until the alert is lifted.

Several people were injured at a hotel in the Aomori town of Hachinohe and a man in the town of Tohoku was slightly hurt when his car fell into a hole, public broadcaster NHK reported.

Kihara said nuclear power plants in the region were conducting safety checks and that so far no problems were detected.

Several cases of fires were reported in Aomori and about 90,000 residents were advised to take shelter at evacuation centres, the Fire and Disaster Management Agency said.

Satoshi Kato, a vice principal of a public high school in Hachinohe, told NHK that he was at home when the quake struck and that glasses and bowls fell and smashed into shards on the floor.

Kato said he drove to the school because it was designated an evacuation center, and on the way he encountered traffic jams and car accidents as panicked people tried to flee. Nobody had yet come to the school to take shelter, he said.

Prime Minister Sanae Takaichi said the government had set up an emergency taskforce to urgently assess the extent of damage.

"We are putting people’s lives first and doing everything we can," she said.

The quake struck about 80 kilometres northeast of Hachinohe and about 50 kilometresbelow the sea surface, the meteorological agency said.

It was just north of the Japanese coast that suffered the magnitude 9.0 quake and tsunami in 2011 that killed nearly 20,000 people.