Firefighters have been on the scene since Monday to put out the fire that affected over 65 hectares of land in the park.
No report has yet been released on the extent of damage to the site.
Earlier in June, bushfires burned large swathes of the forests in the area which took several days to extinguish.
Drought, human factors, and the burning of wheat fields by farmers are the main causes of fire in the Karkheh forests.
The Karkheh National Park is the main habitat of the Persian yellow deer.
