RALEIGH, N.C. (WNCN) — A large fire in North Raleigh at a landfill on the city’s border with Wake County is continuing for at least the fourth day — and initial reports appear to indicate the fire did not start as a controlled burn.

Large, dark smoke-filled clouds were seen beside Interstate 540 near Gresham Lake Road again Monday, following the start of the fire very early Friday morning.

The blaze of trees, stumps and limbs at Wall Recycling Raleigh is part of a controlled burn, company and Raleigh fire officials said.

But, the fire has triggered many complaints over Thanksgiving and the weekend.

Some people said the smoke has a bad smell while others also complained about ashes on cars and other items outdoors. Some others complained of breathing problems from the smoke.

Raleigh crews responded to at least four calls by residents about smoke on Friday and Saturday that turned out to be linked to the landfill fire, according to reports.

The Raleigh Fire Department now says they are not sure how the fire started. A call about a blaze in the area was first noted around 3:25 a.m. Friday, according to a Raleigh Fire Department report.

In that call, the incident was called “large” and was not noted as a controlled burn.

About five hours later on Friday, city and Wake County fire crews were called back to the scene.

At that point, the fire was not under control, according to a Raleigh Fire Department report.

The report said officials “arrived on scene and found workers actively working to control the mulch fire with making a fire break.”

NCDOT image on Friday afternoon of smoke from the fire drifting over I-540.

Saturday, the company and Raleigh fire officials said there was a permit for a controlled burn.

Wake County fire officials said the burn permit came from the North Carolina Division of Air Quality.

The Department of Environmental Quality clarified on Tuesday that it does not issue open-burning permits to businesses.

“Wall Recycling has a permit from the Division of Air Quality to operate an air curtain incinerator, a device that burns wood and brush with less smoke and emissions than open burning. The fire at the facility was not associated with the incinerator,” said Shawn Taylor who is the public information officer at the DEQ told CBS 17 by email.

The Division of Waste Management and the Division of Air Quality are working together to investigate and take appropriate action, Taylor said.

It’s not clear when the fire will end.

Raleigh fire officials said such fires can start from spontaneous combustion.

Electronic signs along I-540 started providing info about the fire on Saturday.