Alfreton assault victim urged to come forward
Officers were called to Institute Lane at about 8.35pm on Saturday after receiving reports that a man had been punched.
A 15-year-old girl was arrested on suspicion of a public order offence and has been bailed pending further inquiries.
Police investigating the incident are no appealing for the victim to come forward.
Anyone with information should call Derbyshire police on 101, quoting crime reference 19540/15, or Crimestoppers anonymously on 0800 555 111.