Crews from Suffolk Fire and Rescue Service have been struggling to reach a combine harvester described as being “well alight”.
Three crews from Long Melford, Clare and Newmarket have been at the scene in Withersfield, near Haverhill for more than three hours.
They arrived at 5.07pm following reports of a combine harvester on fire in a field.
An ambulance has also been called to the scene, although the extent of any injuries is not currently known.
A spokeswoman for the fire service said crews have had difficulty accessing the machine and have called for a water bowser to be dispatched.
She added the combine harvester is "well alight".
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