PILOT MOUNTAIN, N.C. (AP/WAVY) — Authorities say a wildfire at Pilot Mountain State Park in North Carolina has grown to more than 1,000 acres — twice its size of a day earlier.

News outlets report that officials said Tuesday that the blaze on Pilot Mountain is about 20% contained and is burning only inside the park.

The park is northwest of Winston-Salem, North Carolina, and is known for its iconic knob that rises above the surrounding terrain.

North Carolina Forestry Service officials say the fire started Saturday near a trail and was human-caused.

Law enforcement officers are investigating to determine just how the blaze was begun. The park remains closed.

The state Forest Service has issued a burn ban across North Carolina due to hazardous forest fire conditions.

The ban went into effect Monday. It prohibits opening burning in all of North Carolina’s counties regardless of whether a permit was previously issued.