Four teenagers have been arrested on suspicion of robbery after the video of an alleged attack on a man in Bridgwater was shared widely on social media.
Police say they received a call at 11.15pm last night, Tuesday 12 May, about the video.
Those arrested are all in custody. They are a 17-year-old female, a 17-year-old male and two 16-year-old males.
Officers say they have identified a fifth person believed to be linked to the incident, which took place on Monday night, 11 May.
Police have met the victim and say his injuries are not considered to be life-threatening or life-changing but he is going to hospital as a precaution.
They are looking at CCTV and conducting house-to-house enquiries.
Officers have appealed for people not to share the video on social media or name anyone involved publicly.
Anyone who witnessed what happened is asked to call 101, or report it online, giving reference number 5220103361.