Heavy rain pounded much of the country Monday, leaving roads flooded and many residents evacuating for safety, as rescue efforts are under way to find a person missing in the central county of Okcheon following a landslide.

In Yeongyang county in North Gyeongsang Province, 55.5 mm of rainfall hit the region in an hour from 3 a.m., and 52.5 mm of downpours per hour had been recorded as of 3:30 a.m. in nearby Andong, 192 kilometers southeast of Seoul, according to the Korea Meteorological Administration (KMA).

Emergency texts warning of the heavy downpours were sent to residents in nearby regions early Monday, the first time such warnings sent outside of the capital area.

As of 10 a.m., 197 people from 129 households had evacuated in the Gyeongsang Provinces.

Heavy overnight rain stranded 25 residents of rural villages in Andong, and a nearby county early Monday morning. All of them were safely rescued by emergency rescuers or evacuated on their own.

Firefighting authorities expect the number of those stranded or fleeing for safety could increase, as many roads in northern parts of North Gyeongsang Province were off-limits due to flooding.

A resident in his 50s from Okcheon, 149 kilometers south of Seoul, went missing Monday morning while inspecting his home amid a landslide affecting his backyard, according to firefighters. Rescuers were having difficulties combing through the backyard in search of the missing person due to flooded soil.

In South Chungcheong Province, 78 residents living in areas vulnerable to landslides or collapsing of retaining walls were evacuated to safety.

Two drivers, in their 70s and 40s, were rescued by firefighters in the central city of Daejeon after their vehicles became waterlogged and they could not get out.

The Central Disaster and Safety Countermeasures Headquarters, the country's disaster control tower, activated the first stage of its three-stage response posture, while the heavy rain alert was raised to "caution," the second-highest level in the four-level system, according to the interior ministry.

The downpour also knocked down street trees in the central city of Daejeon and flooded a road in the nearby city of Nonsan, while soil runoff on a road was reported in Geumsan.

Interior Minister Lee Sang-min, who heads the disaster control tower, instructed regional governments, police and firefighters to "maintain their emergency response readiness and be prepared to take immediate initial action at the signs of perceived risks."

The KMA said that central regions, as well as northern parts of North Jeolla and North Gyeongsang provinces, would experience up to 50 mm of rainfall per hour during the day, accompanied by gusty winds, thunder and lightning.

Those regions are expected to receive up to 120 mm of rain Monday, while the capital region and inland and mountainous areas of Gangwon Province are likely to see accumulated precipitation between 30 and 80 mm.

Most parts of the country will also experience rainy weather through Wednesday, the weather agency said. (Yonhap)