A big quake off northern Japan left at least 30 injured, authorities said Tuesday, damaging roads and leaving thousands without power in freezing temperatures.The Japan Meteorological Agency said the magnitude 7.5 quake at 11:15 pm on Monday (1415 GMT) -- downgraded from 7.6 initially -- raised the chances of similar or larger tremors in the coming days.Prime Minister Sanae Takaichi said 30 people were injured in the quake off the coast of the Aamori region, which triggered tsunami waves up to 70 centimetres (28 inches) high.

The injured included one person seriously hurt in the main northern island of Hokkaido, according to the Fire and Disaster Management Agency.Footage showed several crevasses in roads and at least one car in a hole, with broken glass from windows scattered on roads and pavements.Initially there were reports of several fires. Government spokesman Minoru Kihara said Tuesday that was one confirmed blaze at a house.

In Hokkaido,  reporter said the ground shook violently for around 30 seconds as smartphone alarms rang to alert residents.Daiki Shimohata, 33, a civil servant in Hashikami in the Aomori region on Honshu island, told  that he and his family rushed outside their home."The tremor was something that we've never experienced. It lasted maybe for about 20 seconds," Shimohata said by phone."We were holding our children -- a two-year-old girl and a one-year-old boy -- in our arms.

The shaking reminded me of the disaster (in 2011)," he said. Some 28,000 people were advised after the quake to evacuate from their homes, emergency services said, and media reports said some makeshift shelters were full.With temperatures around freezing point, some 2,700 homes in Aomori were without power, Kyodo News reported in the hours after the quake.

Credit: Independent News Pakistan (INP)