A man was knocked unconscious after being kicked, punched and having a glass bottle smashed over his head in an unprovoked assault.
The 41-year-old victim had to have two teeth removed as a result of the attack, which occurred in an alley off Lock Close in Kirk Hallam on Sunday July 29 at around 10.15pm.
Police are keen to speak to two men who were seen in the area when the assault took place.
One of the men is described as being white, tall and with light coloured hair. The other man is described as white, with short dark hair and was wearing a short sleeved, navy Adidas t-shirt that had a large white logo on the front.
Anyone with any information is asked to contact police, quoting the reference number 18000358197 and the name of the officer in the case PC Munday, by calling 101, or filling in the online contact form at www.derbyshire.police.uk/Contact-Us.
Alternatively, call Crimestoppers anonymously on 0800 555 111.