The government is investigating if human activity, including tomb-cleaning fires and welding sparks, sparked some of the blazes.

The pilot was killed when a helicopter crashed Wednesday during South Korea's efforts to contain wildfires in the town of Uiseong.

The death toll in the wildfires raging across South Korea's southeastern region rose to 24 and the pilot of a firefighting helicopter was killed when the aircraft crashed on Wednesday, as the country battles some of its worst forest fires in decades.