Firefighters have resumed efforts to put out a wildfire in the northeastern town of Yanggu in Gangwon Province that broke out on Thursday afternoon.

Local fire authorities said that as of 5 a.m. Friday, 50 percent of the fire, which broke out at 4:32 p.m. the day before, has been extinguished with the affected area estimated at one hectare.

The authorities deployed six helicopters at 6:50 a.m. on Friday shortly after sunrise to completely put out the fire, having grounded them the previous night to continue efforts with a special team in the lead that encountered difficulties due to the rugged terrain.

Authorities plan to investigate the cause and extent of damage as soon as the fire is extinguished.