A man was left with a “significant head wound” after he was struck with a glass bottle.
The incident, which occurred around 9.55pm on Saturday, took place in Old Street, Kilmarnock.
The man, 34, was taken to University Hospital Crosshouse for treatment following the assault.
The suspect has been described by police as white, between 16 and 22 years old, around 5ft 8in tall, and was seen on a white bicycle in Low Glencairn Street prior to the assault.
Detective Constable Lee Duncan of Police Scotland said: “This was an unprovoked attack which has left the victim with a significant head wound requiring multiple stitches.
“We know that Low Glencairn Street was particularly busy when the suspect was seen riding his bicycle and I would like to speak to anyone who may have seen him either before, during or after the assault took place.
“Anyone with dashcam or CCTV footage could have captured the suspect or assault and if so, I ask that they contact police immediately.”
Anyone with information should call police via 101 and quote incident number 1134 of Sunday, March 1 2026.
Alternatively contact Crimestoppers on 0800 555 111, where anonymity can be maintained.
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.