A teenager remained in custody on Thursday morning after being arrested on suspicion of assault after two men were stabbed near Norwich railway station.
Six police vehicles were called to Riverside Road, at the junction with Thorpe Road, along with the ambulance service after two men were stabbed on Wednesday.
Police were called to reports of an altercation at the railway station just before sunset, around 3.20pm.
The men suffered knife wounds and were taken to the Norfolk and Norwich University Hospital for treatment where their condition was described as stable.
A teenage girl from the Norwich area was arrested in connection with the incident and remained in custody Thursday morning.
Detective Inspector Chris Burgess said: 'We are still in the early stages of our investigation and our enquiries remain ongoing to fully understand the circumstances surrounding the incident.
'There has been an increased police presence in the area and will be for some time as our investigation continues.'
Cars and buses were diverted as the rush hour traffic filled the roads. Commuters emerged and passers-by were redirected away from cordoned-off areas, including the riverbank closest to the railway station.
Scores of people watched from behind police tapes as officers stood at various points around the junction where splatters of blood could be seen on the ground and on the wall close to Pizza Oro in Thorpe Road.
A witness, who preferred to remain anonymous, said: 'All we saw was the two men being taken away in an ambulance.
'I think everybody is just shocked because it just seems like such an unusual thing to happen in the afternoon.
'It looked quite serious.'
Another businessperson in the area, who did not want to be named, said: 'We have had to deal with stuff like this before, like the Rose Lane stabbing a couple of months ago.
'It seems to be getting worse, we need more policing in the area.'
While the railway station remained open, Thorpe Road, near the junction of Riverside, had been closed and some bus services were suspended.
Anyone with information should contact Norfolk Constabulary on 101 or contact Crimestoppers anonymously on 0800 555 111.
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