A powerful 7.6-magnitude earthquake struck late Monday off northern Japan, triggering a tsunami of up to 70 centimeters (27 inches) in Pacific coast communities and warnings of potentially higher surges, the Japanese Meteorological Agency said.

Several people were injured, according to media reports, and residents in some coastal areas were urged to head to higher ground or take shelter inside buildings or evacuation centres.

Prime Minister Sanae Takaichi, in brief comments to reporters, said the government has set up an emergency task force to urgently assess the extent of damage.

The quake struck at about 11:15 p.m. (1415 GMT) in the Pacific Ocean about 80 kilometres (50 miles) 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 3 meters (10 feet) in some areas, and urged people to be "fully alert" for possible further quakes over the next few days.

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.

Chief Cabinet Secretary Minoru Kihar 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 centers, the Fire and Disaster Management Agency said.