Typhoon Hagibis has wreaked havoc in wide areas of Japan, leaving at least 14 people dead and more than a dozen missing as record rains flooded rivers and triggered landslides.
More than 120 people were injured as Hagibis, one of the most powerful typhoons to hit the Tokyo region in decades, made landfall in the Izu Peninsula, hitting the capital Saturday evening.
Rescue operations are underway in many parts of the country which were hit by landslides and widespread flooding.
Torrential rains inundated at least 14 rivers in the northeast and in the regions of Kanto and Koshin, according to broadcaster NHK.
The bank of the Chikuma River collapsed, causing massive flooding in residential areas in the cities of Nagano and Chikuma with authorities estimating that some of the areas may see floodwaters of up to five metres deep, Kyodo News reported.
An emergency rain warning was issued for a total of 13 prefectures on Saturday, including Tokyo and Shizuoka, government spokesman Yoshihide Suga told a news conference.
This year's 19th typhoon "brought a disaster to extremely broad regions", Suga said on Sunday.
About 376,000 households remain without power and 14,000 without water supply, Suga added.
The government is "doing its utmost" to engage in search-and-rescue operations and recovery efforts, he said.
A tornado touched down in the city of Ichihara, east of Tokyo, early on Saturday, killing one person, injuring eight others and destroying 12 houses, Kyodo said.
Overnight, more than 4.4 million people were ordered to evacuate their homes in eastern and north-eastern Japan, including 910,000 in the city of Kawasaki, as the storm brought heavy rains and powerful winds, inundating residential areas.
In Tokyo, about 80,000 residents spent the night at emergency shelters amid fears of massive flooding.
About 800 flights for Sunday have been cancelled following the cancellation of more than 1,600 flights on the previous day, NHK reported.
On Sunday Hagibis was over the Pacific, off the coast of north-eastern Japan, travelling north-east at 60km/h with maximum sustained winds of 108km/h and gusts of 142km/h, the agency said.
Rugby World Cup organisers cancelled a match between Namibia and Canada in the northern Japanese city of Kamaishi on Sunday, while three other games will go ahead as scheduled, officials said.
The game at Kamaishi Recovery Memorial Stadium is the third match to be called off due to the storm.