Firefighters were called to a fire involving a large barn on a farm in Cressing.
Initially, two fire engines were sent to the incident at the field on Braintree Road this morning but when they got there the officer requested the assistance of two more fire engines.
The barn contained hay and palletts. Crews tacked the fire on multiple fronts. They also moved a number of argricultural machinery and horse boxes away from the fire to protect them.
At 4am, the crews changed shifts. Fire engines from Tiptree, Maldon, Thaxted, Leaden Roding took over the scene.
At 9am, fire officers reported steady progress is being made.
The fire is issuing a lot of smoke, and because the wind has changed direction, there is a lot of smoke blowing over the road (main road from Witham to Braintree) and towards a housing estate.
Fire officers are advising nearby neighbours to keep their windows and doors shut.