Record heavy rains hit South Korea's southern regions Tuesday evening and Wednesday morning, leaving at least four dead and one missing, with weather authorities saying it was the most intense downpour in 200 years.

Heavy rains battered parts of North Jeolla Province starting early Wednesday. Gunsan received 131.7 millimeters of rain within one hour to 2:24 a.m., the heaviest hourly downpour recorded nationwide. The hourly precipitation accounted for over 10 percent of the city's average annual rainfall of 1,246 mm.

Notably, the figure was the highest in 117 years, since weather record-keeping began in 1907. The Korea Meteorological Administration said the intensity of the overnight rainfall was at a level that occurs "once every 200 years."

The nearby island of Eocheongdo, west of Gunsan, received 146 mm of rain in about an hour from 11:51 p.m. on Tuesday. The last time rainfall exceeding 140 mm within an hour occurred in this area was July 31, 1998.

Heavy rains also wreaked havoc on multiple areas where the highest rainfall intensity exceeded 100 mm in an hour. These areas include Iksan, also in North Jeolla Province, which saw 125.5 mm of rainfall; and Seocheon and Buyeo in South Chungcheong Province, which received 111.5 mm and 106 mm of rainfall, respectively.

Torrential rains flooded a studio apartment building in Nonsan, South Chungcheong Province, at 3 a.m. on Wednesday, leaving one man dead in an inundated elevator. Fire authorities retrieved the man's body and were trying to confirm his identity.

At 3:57 a.m., a house collapsed in a landslide in Seocheon-gun. Fire officials said a man in his 70s was found inside the house in cardiac arrest. He was moved to a hospital but pronounced dead an hour later.

Another man in his 70s died in Okcheon, North Chungcheong Province, after his car plunged into a swollen stream at 5:04 a.m. Yet another man in his 60s in Daegu was found dead after his wife discovered he had been sucked into a drainage pipe while checking on his vegetable field.

In the South Chungcheong Province county of Geumsan, a woman in her 60s was found dead in her mud-filled house following a landslide.

Authorities were searching for a 71-year-old man who went missing in Yeongdong, North Chungcheong Province, after his container shed floated away and his vehicle was found submerged due to the rains.

Hundreds of people evacuated their homes as massive monsoon rains hammered the country.

In Wanju, North Jeolla Province, rescuers evacuated 18 villagers -- mostly in their 70s and 80s -- who were stranded due to a swollen stream.

A village in Nonsan was flooded, leaving some 30 residents having to evacuate to a nearby village hall for safety. Due to the heavy rains, some 40 residents in nearby Ganggyeong were also evacuated.

The entire community of Yongchon-dong in Daejeon was inundated, with 27 houses flooded and 36 people left stranded. Authorities immediately dispatched rescue boats and were carrying out operations to rescue them.

A total of 76 households and 94 residents in South Gyeongsang Province were also relocated to nearby village halls, community centers and churches overnight, following a flood alert issued when the water level of the Nakdong River rose rapidly.

As of Wednesday afternoon, the downpours had damaged 391 public facilities and 146 private facilities, according to the Central Disaster and Safety Countermeasure Headquarters. These include flooded roads, soil runoff from landslides, submerged bridges and waterlogged vehicles and houses. It added that 3,568 people from 2,585 households had been evacuated for safety reasons.

Torrential rains also led to delays and cancellations of flights and trains.

Korea Railroad Corp. said Wednesday that it had partially suspended or adjusted operations for Mugunghwa and ITX-Saemaeul trains, starting from the day's service.

Train services on the Janghang Line in South Chungcheong Province and the Gyeongbuk Line in North Gyeongsang Province were suspended until 6 p.m., while the Chungbuk Line halted services until 9 a.m. on Wednesday.

In addition, some 21 flights at Gimhae International Airport had been canceled and 16 others had been delayed due to strong winds as of Wednesday at 7 a.m.

As heavy rains drenched the nation, President Yoon Suk Yeol, who is currently visiting the US, ordered the "mobilization of all personnel and equipment available" under the leadership of the interior minister to "prioritize saving lives and preventing further damage," according to his spokesperson, Kim Soo-Kyung.

During a government response meeting on the same day, Interior Minister Lee Sang-min said the government must concentrate all of its capabilities to minimize damage, given that the monsoon season is far from over. The ministry raised the emergency operations of the disaster control office from level 1 to 2, he said, as of 2:30 a.m. Wednesday.

"Relevant agencies, including central government ministries and local governments, should prepare for 'worst-case' scenarios and respond to disasters accordingly. ... Please make all-out efforts so that the victims of the heavy rain can quickly return to their daily lives," Lee said.