A brush fire on Quantico Marine base is responsible for a smoky smell and ash in the county.
Base officials said crews were battling a fire "crawling through the woods" in a training area on the west side of the base on Tuesday.
"The affected area was too large to extinguish outright so emergency responders limited the spread of the fire by bulldozing a 'no burn' zone around it," base officials said.
Prince William County police on Wednesday night said the wildfire covered in excess of 2,000 acres on the base side of Aden Road. A thick column of smoke could be seen on the horizon along the Va. 234 bypass outside Manassas Wednesday afternoon.
GALLERY: Photos from the fire
Firefighters used a technique called "back-burning" to battle the blaze. Officials describe back-burning as "a controlled burn designed to rob the fire of fuel so it can be managed safely."
As of Wednesday night, crews are still on the scene.
"The safety of the population aboard the base and the surrounding areas is our number one priority and the responders will stay on the scene until the fire is extinguished," Cpl. Antwaun L. Jefferson said.
Many Prince William County residents smelled the smoke and saw ashes falling in their neighborhoods.
Prince William County Fire and Rescue Department Battalion Chief Curtis Brodie confirmed the smoke was a result of the brush fire at Quantico.