A blind woman in her 70s was assaulted after being subjected to abuse while travelling on a bus from Chippenham to Melksham.
The victim was repeatedly shouted at by a man before he hit her in the head during the journey on the Faresaver X34 service.
The incident happened on Saturday 11 July on the bus, which left Chippenham at around midday heading towards Frome.
The woman boarded the bus in Chippenham and got off in Melksham.
Wiltshire Police said there is no CCTV available and officers do not have a description of the suspect.
Officers are keen to hear from anyone who was travelling on the bus at the time and may be able to help identify the man.
Anyone with information is asked to call 101, quoting crime reference number 54260087276.
Information can also be passed anonymously to CrimeStoppers by calling 0800 555 111.
