The severest damage has been concentrated in South Korea’s central and southern regions.

In the central city of Cheongju, hundreds of rescue workers, including divers, continued to search for survivors in a muddy tunnel where about 15 vehicles, including a bus, got trapped in a flash flood that may have filled up the passageway within minutes on Saturday evening.

The government has deployed nearly 900 rescue workers to the tunnel who have so far pulled up 13 bodies and rescued nine people who were treated for injuries. It wasn’t clear how many people were in the submerged cars.

As of Monday afternoon, rescue workers had pumped out most of the water from the tunnel and were searching the site on foot, a day after they used rubber boats to move and transport bodies on stretchers.

Hundreds of emergency workers, soldiers and police were also looking for any survivors in the southeastern town of Yecheon, where at least nine people were dead and eight others listed as missing after landslides destroyed homes and buckled roads, the county office said.