About 200 bales of hay have caught fire in a field near a holiday park.
Fire crews were called to Church Lane, East Mersea, at 8.45pm on Sunday.
The blaze, which is in a field near Coopers Beach Holiday Park, has spread to a nearby hedgerow.
Firefighters remained on the scene at 10.30pm.
UPDATE: Crews using a hose reel and two backpack sprayers had extinguished the fire by 12.15am on Monday.