Police would like to speak to anyone who witnessed a man being assaulted in Brett Street, Bridlington, at 7.10pm on Wednesday, June 5.
A 39-year-old man was walking along the street, when an unknown man punched him in the face, whilst passing him in the opposite direction.
The two men did not speak to each other at any point and the offender continued on his journey immediately after the incident.
The victim sustained reddening to his cheek bone and has a swollen left eye.
The offender is described as a white male, of a slim build and 5ft 8ins tall. He is thought to be aged in his 20s and he was wearing a black hooded top with a red trim.
If you saw the incident or you have information about the assault, please call Humberside Police on 101, quoting crime reference 1978335. Alternatively, speak to Crimestoppers on 0800 555 111 to give the information anonymously.