A fire on the Drumnacanvy Road, Portadown, is under control, according to the Fire Service, but the incident is expected to last into the early evening.
Firefighters were called to the blaze at a large industrial unit near Knocknamuckly this morning.
Residents in the area have been asked to close all windows and doors as a precautionary measure.
Said a spokesperson, “The call was received at 11.51am today and there are currently five fire appliances and 23 firefighters in attendance.
“The Drumnacanvy Road is currently closed and the incident is ongoing.”