Seoul. South Korean rescuers on Sunday pulled nine 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 across the country, officials said.

A total of 37 people have died and thousands have been evacuated since July 9, when heavy rain started pounding South Korea's central regions.

Nearly 900 rescuers including divers were searching the tunnel in the central city of Cheongju, where the vehicles, including a bus, were swamped by a flash flood Saturday evening, Seo Jeong-il, chief of the city’s fire department, said in a briefing.

Fire officials estimated that the tunnel filled with water in as little as two or three minutes.

Photos and video from the scene showed rescue workers establishing a perimeter and pumping brown water out of the tunnel as divers used rubber boats to move in and out of the area.

Yang Chan-mo, an official from the North Chungcheong provincial fire department, said it could take several hours to pump out all the water from the tunnel, which was still filled with 4 to 5 meters (13 to 16.4 feet) of water dense with mud and other debris. Workers were proceeding slowly to prevent any victims or survivors from being swept out, Yang said.

Nine survivors were rescued from the tunnel and around 10 others were believed to be missing based on reports by families or others, but the exact number of passengers trapped in vehicles wasn’t immediately clear, Seo said.

More than 60 centimeters (23.6 inches) of rain was measured in the South Chungcheong provincial towns of Gongju and Cheongyang since July 9. Cheongju, where the tunnel is located, received more than 54 centimeters (21.2 inches) during the same period.

The Korea Meteorological Administration said the central and southern parts of the country could still get as much as 30 centimeters (12 inches) of additional rain through Tuesday.

More than 8,850 people have been evacuated and 27,260 households had been without electricity in the past several days. The rain damaged or destroyed nearly 50 roads and more than 100 homes, the Ministry of the Interior and Safety said. At least 35 people were treated for injuries.