Police are searching for witnesses who saw a group of people hanging around a bowling alley just before two men were stabbed near Norwich railway station.
Police were called to Thorpe Road on Wednesday to reports of an altercation at the station that had started at the nearby Hollywood Bowl.
Two men, who suffered knife wounds, are in hospital in a stable condition.
Norfolk Police appealed to anyone who saw the group walking towards the station at 15:00 GMT to contact them.
A 16-year-old girl, arrested on suspicion of assault, remains in custody.