Thames Valley Police is appealing for witnesses following three incidents of sexual assault in Milton Keynes.
The incidents all occurred in shops in Central Milton Keynes shopping area between Tuesday 5 April and Friday 8 April.
On all three occasions, the offender touched the bottom of the victims as he walked past.
Investigating officer, Detective Sergeant Adam Billingham, based at Milton Keynes police station, said: “We are appealing for witnesses to any of these incidents to get in touch with us.
“Anyone with information should call 101 or make a report on our website, quoting reference 43220152404.
“Alternatively, if you wish to remain anonymous, you can contact the independent charity, Crimestoppers, on 0800 555 111 or via its website.”