Knoxville authorities are looking into what appeared to be the deliberate burning of a semi-tractor late Wednesday at the Tennessee Highway Patrol impound lot.

Knoxville Fire Department spokesman Capt. D.J. Corcoran told 10News that KFD responded about 11 p.m. Wednesday to a call at the lot at 3415 Huron St.

The Volvo semi-tractor was being "stored there as evidence in an ongoing investigation by our agency," according to THP spokesman Lt. Don Boshears.

Boshears said he didn't know if any suspects had been identified, and he referred questions to Knoxville Police Department.

Corcoran said, "Our arson division is investigating it as a set fire."

He asked that anyone with information about the fire call KFD at 865-595-4480.