Firefighters on Monday resumed efforts to contain a wildfire that broke out the previous day in Yanggu in Gangwon Province.

Authorities mobilized 13-hundred firefighters and 27 helicopters at 6 a.m. on Monday to extinguish the fire that started in Songcheong-ri area in Yanggu at around 3:40 p.m. on Sunday.

According to the Korea Forestry Service, 521 hectares of forest were estimated to have been scorched in the fire. The burned areas are equivalent to about 730 soccer fields.

Authorities mobilized about 300 firefighters and 15 helicopters on Sunday but had difficulties putting out the fire due to winds as strong as over ten meters per second.

The fire prompted the evacuation of about 50 local residents, but no casualties were reported. The wildfire reportedly started when a man in his 50s was burning fallen leaves.