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.

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, 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 the Raleigh Fire Department website.

In that call, the incident was called “large” and was not noted as a controlled burn. Saturday, the company and Raleigh fire officials said there was a permit for a controlled burn.

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

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

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.