Typhoon Roke makes landfall on the shores of Wakayama Prefecture in central Japan.
The category two storm pummelled the shore with heavy rain and strong winds.
As the typhoon moved through Japan's industrial heartland towards Tokyo, one broadcaster reported four people were confirmed dead and two missing following floods and landslides triggered by the storm.
The Japanese government warned all those in the path of the typhoon to heed any evacuation orders immediately.
(SOUNDBITE) (Japanese) JAPANESE CHIEF CABINET SECRETARY, OSAMU FUJIMURA:
"We need to be extra vigilant against a potential disaster caused by heavy rains, strong winds and rough seas along a wide area from western to northern Japan."
Although local authorities have been reinforcing defences, a large part of central Japan has still been flooded.
Over a million residents around the city of Nagoya were advised to evacuate, and relief workers had to rescue some residents after rising waters cut off whole parts of the city.
(SOUNDBITE) (Japanese) UNIDENTIFIED EVACUEE:
"The water levels got to right under the bridge. I was so totally taken aback that when I saw it, I ran home. That's when I saw there was an evacuation advisory."
Tokyo Electric Power Company said the typhoon had not yet affected its Fukushima Daiichi nuclear power plant, where work is underway to protect the damaged reactors from the elements.
Engineers are still struggling to bring the plant under control following the meltdown and radiation leak caused by the March 11 earthquake and tsunami, and there are concerns the heavy rain could wash further radioactive material into the sea.
Nick Rowlands, Reuters.
