Firefighters are working to contain the main flames of a massive wildfire in eastern coastal areas on Monday as the blaze ravages the areas for a fourth day.

The Korea Forest Service(KFS) plans to mobilize 53 helicopters and about five-thousand people at daybreak on Monday.

The KFS aims to put out the main flames within the day as the weather conditions are forecast to worsen from Tuesday afternoon.

The blaze began on Friday morning on a road near a mountain in Uljin County, North Gyeongsang Province, and spread north to its neighboring city of Samcheok in Gangwon Province in the afternoon, driven by strong winds and dry weather.

The fire further spread to the southern areas of Uljin on Saturday, and moved toward the Geumgang Pine Habitat in Uljin, a natural heritage site on Sunday.

Forest authorities managed to prevent the blaze from reaching the natural heritage site and residential areas overnight, mobilizing over 18-hundred people and some 760 firefighting apparatuses, including fire trucks.