Officers were called to three neighbouring business units at The Crescent in Severalls Park, Colchester after intruders attempted to remove external air conditioning units.
But the suspects are believed to have fled empty handed after signs that one or more of them might have been electrocuted while cutting through power cables.
Investigating officer Pc Luke Howard said: “It would appear that several people were involved in this attempted theft because electrical wires were cut to various conditioning units.
“However, an engineer who attended the scene believes that one or more of the culprits could have suffered a serious electrical shock and perhaps this is why they left empty-handed.
“We want to hear from anyone with information about the incident or from anyone who knows anyone who has unexplained burns.”