Two men were taken to hospital after being stabbed in the early hours of Friday.
Police were called to a popular clubbing street in Norwich shortly before 5am.
Two men in their 20s suffered serious injuries on Prince of Wales Road.
One had a stab wound to his chest and the other to his shoulder.
Two men, both aged in their 20s, were arrested at the scene. Another two men, also in their 20s, were arrested in Enfield in London at 9am.
A cordon was set up closing St Vedast Street, which connects Prince of Wales Road to Rose Lane.
Anyone with information is being asked to contact Norfolk Police.