Typhoon Halong has slammed into Japan’s western main island after Japan’s weather agency issued its highest alert as the storm lashed the southwest of the country.

The strong typhoon made landfall near Aki, Kochi prefecture, on Shikoku island at around 7am AEST this morning, an official at the Japan Meteorological Agency said.

Late on Saturday, the agency issued its highest warning for Mie prefecture, some 300km west of Tokyo, as the outer bands of the storm were already lashing the region and other areas of southwestern Japan, the agency said.

The warning means that the storm poses a threat to life and could inflict massive damage, the meteorological agency said.

Storms and torrential rain earlier this week have left one dead and 25 injured, public broadcaster Japan’s public broadcaster NHK said.