Manila, April 17 -- The damage from massive wildfires last month in South Korea's North Gyeongsang province is twice the initial government estimate, officials said Thursday.

The wave of forest fires burned nearly 90,000 hectares of land in five cities and counties in the province, according to a government-led joint investigation.

Initially, the Korea Forest Service put the estimated damage at 45,157 hectares, Yonhap News Agency reported.

The wildfires, which also affected South Gyeongsang province, destroyed an estimated 4,000 structures, including the 1,300-year-old Gounsa Temple - a UNESCO World Heritage Site - along with homes and factories.

The damage is sharply higher than the 23,794 hectares burned by wildfires on the east coa...