A man is seriously ill in hospital after he was attacked in a street in Bath.
Police say the 32-year-old man suffered a serious head injury in the assault, which happened in Quiet Street at 2030 BST on Saturday.
The victim, who has not been named but lives in the London area, remains in a critical condition in the city's Royal United Hospital.
Two men have been arrested on suspicion of causing grievous bodily harm.
Police say the man had attended the Bristol City v Millwall game earlier in the day, but the incident was not football-related.
The force spokesman added: "We urgently need to speak to anyone who saw anything. They may have witnessed some fighting, but haven't reported it to us because they don't realise how badly the victim was hurt.
"We also know that several people gave the man emergency first aid at the scene. It's very important that they contact us immediately."
Detectives are trying to establish what led to the trouble between six men from London and a group of eight men and women, believed to be local.
Anyone who witnessed the incident is asked to contact Avon and Somerset Police.