Helicopters dumped water over a burning forest in South Korea on Thursday as fire crews struggled to contain the country’s worst-ever wildfires, which have killed 26 people, forced at least 37,000 others to flee their homes and destroyed more than 300 structures.

Multiple wildfires fuelled by strong winds and dry weather have been raging across South Korea’s southeastern regions since last Friday. The government has mobilised thousands of personnel, dozens of helicopters and other equipment to extinguish the blazes, but gusty winds are hampering their efforts.