South Korean rescue workers pulled seven bodies from a flooded tunnel where around 15 vehicles were trapped in muddy water, as days of heavy rain triggered flash floods and landslides and destroyed homes, leaving at least 33 people dead and forcing thousands to evacuate, officials said Sunday.

Nearly 400 rescue workers, including divers, were searching the tunnel in the central city of Cheongju, where the vehicles, including a bus, were swamped by a flash flood on Saturday evening, Seo Jeong-il, chief of the city’s fire department, said in a briefing.