A man was dragged to the ground and kicked in the head outside The Buttermarket venue, in Howard Street, at sometime between 2am and 2.30 on Sunday, April 24.
The man was taken to Royal Shrewsbury Hospital and later discharged.
A spokesman for West Mercia Police said: "Officers would like to hear from anyone who was in the area at the time and may have seen the incident or captured in on a mobile phone or dash cam."
Anyone with any information is asked to visit orlo.uk/DYhYi quoting reference 22/39713/22.
Alternatively, if you have information but don’t feel comfortable speaking to police, you can speak to the independent charity Crimestoppers. It is anonymous, they never ask your name and they cannot trace your call or IP address. You can contact them at orlo.uk/jrCxC or 0800 555 111.