RESTRICTED

UWAJIMA, JAPAN - JULY 07:  (CHINA OUT, SOUTH KOREA OUT) In this aerial image, fire fighters checke a collapsed house which was washed away to a beach on July 7, 2018 in Uwajima, Ehime, Japan. 50 people are dead and at least 67 missing in heavy rains that have lashed western Japan since July 3, triggering landslides and flooding in wide areas.  (Photo by The Asahi Shimbun via Getty Images)
PHOTO: The Asahi Shimbun/Getty Images
RESTRICTED UWAJIMA, JAPAN - JULY 07: (CHINA OUT, SOUTH KOREA OUT) In this aerial image, fire fighters checke a collapsed house which was washed away to a beach on July 7, 2018 in Uwajima, Ehime, Japan. 50 people are dead and at least 67 missing in heavy rains that have lashed western Japan since July 3, triggering landslides and flooding in wide areas. (Photo by The Asahi Shimbun via Getty Images)
Now playing
02:32
Catastrophic rainfall kills dozens in Japan
HIROSHIMA, JAPAN - JULY 15:  (CHINA OUT, SOUTH KOREA OUT) Self-Defense Force members continue searching operation on July 15, 2018 in Hiroshima, Japan. More than 100 people were treated for heatstroke as scorching summer heat baked western Japan prefectures hit by recent torrential deluges.  (Photo by The Asahi Shimbun via Getty Images)
PHOTO: The Asahi Shimbun via Getty Images
HIROSHIMA, JAPAN - JULY 15: (CHINA OUT, SOUTH KOREA OUT) Self-Defense Force members continue searching operation on July 15, 2018 in Hiroshima, Japan. More than 100 people were treated for heatstroke as scorching summer heat baked western Japan prefectures hit by recent torrential deluges. (Photo by The Asahi Shimbun via Getty Images)
Now playing
01:38
More than 200 dead as heavy rain pounds Japan
In this picture taken on July 19, 1995, Shoko Asahara (C), head of the doomsday cult Aum Shinrikyo, is transferred from Tokyo police headquarters to Tokyo District Court for questioning.
Seven of 13 members of a cult behind a deadly sarin attack in Tokyo's subway have been moved to different prison facilites, the justice ministry said on March 15, 2018, as speculation grows that they could soon be executed. The official declined to discuss exactly which of the members were moved out of Tokyo, but local media said the cult's guru Shoko Asahara remained in the Japanese capital. / AFP PHOTO / JIJI PRESS / JIJI PRESS / Japan OUT        (Photo credit should read JIJI PRESS/AFP/Getty Images)
PHOTO: JIJI PRESS/AFP/AFP/Getty Images
In this picture taken on July 19, 1995, Shoko Asahara (C), head of the doomsday cult Aum Shinrikyo, is transferred from Tokyo police headquarters to Tokyo District Court for questioning. Seven of 13 members of a cult behind a deadly sarin attack in Tokyo's subway have been moved to different prison facilites, the justice ministry said on March 15, 2018, as speculation grows that they could soon be executed. The official declined to discuss exactly which of the members were moved out of Tokyo, but local media said the cult's guru Shoko Asahara remained in the Japanese capital. / AFP PHOTO / JIJI PRESS / JIJI PRESS / Japan OUT (Photo credit should read JIJI PRESS/AFP/Getty Images)
Now playing
00:31
Cult leader executed for Tokyo sarin attack
Rocket launch fail
PHOTO: Interstellar Technologies
Rocket launch fail
Now playing
00:45
Watch rocket explode seconds after liftoff
YOKOHAMA, JAPAN - JANUARY 08:  Women wearing kimonos gesture at the camera as they leave after attending a Coming of Age ceremony on January 8, 2018 in Yokohama, Japan. Coming of Age Day is a Japanese holiday held every January to celebrate people who have reached 20 - the official age of adulthood in Japan. Yokohama city, with almost 37,000 people turning 20 this year, is holding one of the largest events in the country.  (Photo by Carl Court/Getty Images,)
PHOTO: Carl Court/Getty Images
YOKOHAMA, JAPAN - JANUARY 08: Women wearing kimonos gesture at the camera as they leave after attending a Coming of Age ceremony on January 8, 2018 in Yokohama, Japan. Coming of Age Day is a Japanese holiday held every January to celebrate people who have reached 20 - the official age of adulthood in Japan. Yokohama city, with almost 37,000 people turning 20 this year, is holding one of the largest events in the country. (Photo by Carl Court/Getty Images,)
Now playing
00:33
Japan lowers its age of adulthood to 18
PHOTO: TV Asahi
Now playing
01:08
First 'ghost ships' of 2018 wash up in Japan
Now playing
01:26
Tokyo hosts crying baby sumo festival
Princess Mako (R), the eldest daughter of Prince Akishino and Princess Kiko, and her fiancee Kei Komuro (L), smile during a press conference to announce their engagement at the Akasaka East Residence in Tokyo on September 3, 2017.
Emperor Akihito's eldest granddaughter Princess Mako and her fiancé -- a commoner -- announced their engagement on September 3, which will cost the princess her royal status in a move that highlights the male-dominated nature of Japan's monarchy.
 / AFP PHOTO / POOL / Shizuo Kambayashi        (Photo credit should read SHIZUO KAMBAYASHI/AFP/Getty Images)
PHOTO: SHIZUO KAMBAYASHI/AFP/AFP/Getty Images
Princess Mako (R), the eldest daughter of Prince Akishino and Princess Kiko, and her fiancee Kei Komuro (L), smile during a press conference to announce their engagement at the Akasaka East Residence in Tokyo on September 3, 2017. Emperor Akihito's eldest granddaughter Princess Mako and her fiancé -- a commoner -- announced their engagement on September 3, which will cost the princess her royal status in a move that highlights the male-dominated nature of Japan's monarchy. / AFP PHOTO / POOL / Shizuo Kambayashi (Photo credit should read SHIZUO KAMBAYASHI/AFP/Getty Images)
Now playing
01:49
Princess postpones wedding over 'immaturity'
PHOTO: Reuters
Now playing
01:14
Wild boars take over Fukushima
PHOTO: Space World/Facebook
Now playing
01:05
Fish frozen in skating rink spark uproar
japan pen pineapple apple pen sot_00002612.jpg
PHOTO: CheeYeeTeoh
japan pen pineapple apple pen sot_00002612.jpg
Now playing
01:00
Pen-pineapple-apple-pen an Internet sensation
japan refugees ripley pkg_00013410.jpg
japan refugees ripley pkg_00013410.jpg
Now playing
03:43
Seeking refuge in Japan
(CNN) —  

Heavy rains pounded southwest Japan, triggering flooding and landslides that killed 57 people and forced 2 million others to flee their homes

At least 22 people have been reported missing following the weekend flooding, according to the Fire and Disaster Management Agency of Japan.

“The record rainfalls in various parts of the country have caused rivers to burst their banks, and triggered large scale floods and landslides in several areas,” Cabinet Secretary Yoshihide Suga said Sunday.

People wait to be rescued on the roof of a house in Kurashiki, Okayama prefecture.
PHOTO: Shingo Nishizume/AP
People wait to be rescued on the roof of a house in Kurashiki, Okayama prefecture.

Hundreds of homes have been destroyed or damaged. In all, eight prefectures have been affected, including Kyoto and Hiroshima.

The Japan Meteorological Agency upgraded its alert system to the highest level in large areas of western Japan, while lifting the warning in other regions.

Japanese military personnel evacuate residents in Kurashiki, Okayama prefecture.
PHOTO: Takumi Sato/Kyodo News via AP
Japanese military personnel evacuate residents in Kurashiki, Okayama prefecture.

Japanese public broadcaster NHK reported about 364 millimeters (14.3 inches) of rain fell between 5 a.m. and 7 a.m. in the city of Uwajima – approximately 1.5 times the average monthly rainfall for July.

In Sukumo City in Kochi prefecture, 263 millimeters (10.3 inches) of rain fell in two hours, NHK reported.

Heavy rains caused highway erosion in Hiroshima.
PHOTO: The Asahi Shimbun/Getty Images
Heavy rains caused highway erosion in Hiroshima.

Heavy rain was forecast to continue through Sunday in the west and the east, agency official Minako Sakurai told reporters.

At least 4 million people have been advised to evacuate surrounding areas. Government officials are warning people in affected areas they are at risk for landslides, flooding, wind gusts and other extreme weather conditions.

Japanese Prime Minister Shinzo Abe said 54,000 personnel had been mobilized for search-and-rescue efforts, NHK reported.

CNN’s Junko Ogura contributed to this report.