Farmers and horse owners in have been urged to be on their guard against thieves operating in the county.
Horses and farm equipment are believed to have been the intended targets for suspects involved in two recent incidents in remote areas of the district.
In an incident overnight between Friday, December 15 and the following morning, intruders tried, unsuccessfully, to force their way into a tack room and stables off Tenpenny Hill, Thorrington.
An attempt was also made to break open a storage container at the same time.
It is not known whether the target for the thieves was horses or equipment stored in the tack room.
In another incident near Golden Lane, Thorpe-le-Soken, a pony was found wandering about 150 yards from its field on the morning of Tuesday, December 18. It is suspected that the pony might have escaped during an overnight attempt to steal the animal or to take equipment in the field.
PC Wendy Crowson of the Brightlingsea neighbourhood policing team said: "There have been a number of incidents over the last few months which have included horses being let loose and attempted break-ins in sheds and batteries stolen from electric fences.
"These are happening during the night and normally near lanes that are quiet and secluded. We are urging farmers and owners of horses to be aware and be extra vigilant in keeping watch for any suspicious activity.
"They should also make sure they have secured, gates properly that shed doors are fitted with strong locks and that fencing around horses is safe.
"Most of these lanes are unlit and secluded so we are asking people to ensure that all measures are taken to protect their own property and to report any suspicious behaviour seen.”
Anyone who sees a crime in progress should dial 999 immediately and anyone with other information should contact Pc Crowson or her colleagues at Brightlingsea neighbourhood policing team on 101.