At least 18 people have died as multiple wildfires rage across South Korea's southeastern region, with thousands of firefighters aided by the military deployed in a bid to contain one of the country's worst forest fires in decades.

South Korea’s acting President Han Duck-soo said the wildfires that began last Friday were causing worse damage than many past wildfires.

South Korea’s forest service said thousands of fighters are tackling at least five active wildfire nationwide.