Four teenagers attacked an older man with planks of wood, leaving him needing hospital treatment.
The incident took place on Grosvenor Terrace off Bootham between 7pm and 7.15pm on Saturday April 14.
The victim sustained an injury to his eye and was taken by ambulance to York Hospital where he was treated and discharged.
The youths are described as between 14 and 16 years old. Two were wearing green tracksuits and one had ginger hair.
Another of the group was wearing a white T-shirt and black jeans. He had short dark hair.
One of the youths may have been carrying a bike tyre at the time of the offence.
Do you know them?
A North Yorkshire Police spokesman said: “We are requesting the public’s assistance to help establish the full circumstances surrounding the incident.
“In particular, we are appealing for information which may help us to identify the four youths and would encourage anyone who saw them or who could identify them them to contact North Yorkshire Police.”
Anyone with information that could assist the investigation should contact North Yorkshire Police details below.