Horses had a lucky escape when a blaze broke out in Elstree around 200 yards away from where they were grazing on Saturday.
Dry straw in the fields in Aldenham Road caught fire just after 1.30pm, and crews of eight fire engines spent just under two hours getting the inferno under control.
Police said a man was reported to have been seen in the field earlier, but there is no information to suggest the fire was started deliberately.
The cause is thought to be accidental.
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