Warrington officers are appealing for information from the public following a number of reports of indecent exposures.
Since 28 May officers have received seven separate reports of indecent exposures at various locations across the Birchwood and Culcheth areas of Warrington.
On each occasion the suspect has emerges from a wooded area and exposed himself in from of children and teenagers.
Officers are carrying out a number of enquiries in relation to the incidents − these include house-to-house enquiries, other local enquiries and any relevant CCTV enquiries.
Patrols have been stepped up in the area and officers have been talking to local people and the local school to offer reassurance and to discuss any concerns they may have.
Sergeant Mark Spaven said: "Those who witnessed these incidents have understandably been left very upset by these incidents and the fact that they have all occurred in front of children adds to their concern.
"We take any incidents of this nature extremely seriously and local officers are doing all that we can to trace the man, or men, responsible.
"Patrols have been increased in the local area to actively target the offender and to reassure local residents. We are advising members of the public to be vigilant and to report any suspicious activity to police immediately.
"I would urge anyone who may have witnessed any of these incidents or has seen anyone acting suspiciously in that area to come forward. I would also encourage anyone who may have information in relation to the identity of the offender to get in touch."
Anyone with any information, which might assist officers with their enquiries, is urged to call Cheshire Police on 101 quoting reference number 0717248484.
Information can also be passed on anonymously, via Crimestoppers, on 0800 555 111.