Police are asking motorists to be aware that smoke coming from a blaze on the Woodvale Road in Belfast is reducing visibility.
Around 40 firefighters were tackling the blaze at a business on Woodvale Road in north west Belfast.
The fire was reported to the Northern Ireland Fire and Rescue Service (NIFRS) at 5.30am on Thursday.
In a statement, NIFRS said crews are trying to stop the flames spreading to other properties.
A Northern Ireland Fire & Rescue Service Spokesperson said: "NIFRS received a call to a fire in a commercial property at Woodvale Road Belfast at 05:30hrs this morning. Firefighters are working to extinguish the fire and to stop the spread of the fire to other properties.
"NIFRS has 5 pumping appliances, an aerial appliance, a command support vehicle, supervisory officers and a total of 40 personnel involved in the incident.
"Operations are ongoing and a further update will be issued in due course."