A Japanese government panel says a massive earthquake with a magnitude of 8.8 or more could occur off Japan's northern island of Hokkaido.

Such earthquakes have occurred in the area at roughly 350-year intervals. The last one hit 400 years ago, making the next one very likely imminent.

The panel on Tuesday released the estimated scale and probability of quakes that could occur along the Chishima Trench, based on the latest studies. The trench is east and north of Hokkaido.

The panel said the probability of such a quake in the next 30 years is 7 to 40 percent.

Panel chair Naoshi Hirata, a professor at the University of Tokyo's Earthquake Research Institute, warns that an earthquake like the March 2011 temblor off northeastern Japan could be imminent, and that people in eastern Hokkaido should brace for a huge tsunami.

Source: ANNnewsCH