Firefighters are battling a blaze at an industrial unit at Sywell Business Park
A column of smoke is rising from the blazing fire at the park off Wellingborough Road, near Sywell.
Fire engines and emergency services are on the scene after the blaze broke out at around 12:45pm.
A spokesman for Northamptonshire Police said: "Fire were called about this at 12.47. It’s a location in Sywell Business Park in Wellingborough Rd. They have closed the Wellignborough Rd before Sywell village."
The plumes of smoke can be seen from town centres across the county as well as Rugby and Milton Keynes.
The fire has reportedly broken out at an industrial unit on the aerodrome.
Scott Brown, who works at Collingtree Lighting, based at Sywell Aerodrome, said: "I was having my lunch in my car when I heard little explosions.
"I looked up and saw people staring and pointing at one of the buildings.
"Within 10 minutes the whole building was on fire, and then it spead to a nearby building.
"When the fire brigade arrived they told everyone to evacuate and get back out onto the main street.
"As far as I know, everyone was accounted for and I don't think anyone has been hurt."
Sywell Aerodrome lets out around 44 commercial offices and industrial units on site.
Northamptonshire Police have closed several nearby roads while they deal with the incident, including:
- Glebe Road is shut at the junction with Wellingborough Road
- Holcot Lane is shut at the junction with Overstone Road
- Sywell Road is shut at the junction with Wellingborough Road
Meanwhile, Wellingborough Council has advised residents to keep their windows shut for health and safety reasons.
And hot ash is reportedly falling into gardens in Kettering.
It is not known which business is affected or how the fire started at this stage.
A spokeswoman for East Midlands Ambulance Service said: We received a call at 1.29pm today to Wellingborough Road, Sywell, Northamptonshire to assist with an incident. We sent two paramedics in ambulance cars and our Hazardous Area Response Team and are currently on scene.”