Avon and Somerset Police arrested four people overnight into Sunday, following a serious assault in Midsomer Norton in the early hours of Saturday morning.
An investigation was launched after a 16-year-old boy was reportedly stabbed at about 4am in Excelsior Terrace.
He was taken to hospital, where he remains in a stable condition.
Overnight into Sunday, 30th September, officers arrested four people, all male, a 17-year-old, two 18-year-olds and a 20-year-old in the Radstock area.
Police are particularly keen to hear from anyone who may have filmed the assault incident on mobile phones.
They believe a number of people were in the area at the time who may have film of the incident. Officers are keen for them to contact them as soon as possible.
Anyone with information about the incident should contact Avon and Somerset Police online here or call the non-emergency number 101, quoting reference 5218181183
You can contact the independent charity Crimestoppers anonymously on 0800 555 111 or via their anonymous online form.