A man is critically ill in hospital after being attacked outside a bar in the centre of Leicester.
The assault happened in the early hours of Saturday morning outside Lloyds in the Market Place.
A man has been arrested in connection with the incident.
The victim, a 39-year-old local man, suffered serious head injuries.
The police say they are particularly keen to trace people who helped the victim but who left the scene before the police arrived.
Detective Inspector Tony Merriman says they could prove crucial to the inquiry.