Domestic air and rail services have been cancelled as a powerful typhoon struck parts of western Japan early today.

At least one person was missing and 50 injured as Typhoon Ma-on made landfall bringing winds of at least 100 kilometres an hour.

Japan Airlines cancelled 93 domestic and four international flights, while All Nippon Airways suspended 218 flights. Various internal rail services were halted and bullet trains faced delays of up to 55 minutes.

The typhoon weakened to a tropical storm as it moved on a course taking it over central Japan today, passing south of Tokyo before heading out to sea.

The storm was about 340 miles southwest of Tokyo at 12.50am local time today, the Japan Meteorological Agency said on its website.

An earlier forecast indicated the storm may pass over the crippled Fukushima nuclear plant by tomorrow. The JMA maintained warnings for heavy rains and landslides for Tokyo and Fukushima.

JX Nippon Oil & Energy halted the berthing of vessels at five refineries in eastern and western Japan.