Emergency services were called to Primrose Crescent shortly after 7.35pm on Wednesday evening following reports of a disturbance involving a number of people.
Officers arrived on scene to find four people with injuries. Despite treatment by paramedics, a man was pronounced dead at the scene.
Three other people were taken to hospital for treatment of suspected knife wound injuries.
Police arrested two men at the scene in connection with the incident who will be questioned in due course.
Superintendent Tracey Little said: “A number of police resources, including armed units, were deployed to the scene.
“A murder investigation has been launched and we are in the early stages of our enquiries to establish the circumstances surrounding the incident.
“We would like to hear from anyone who may witnessed the incident or has information concerning it.”
Police have cordoned off the scene in Primrose Crescent while enquiries are carried out.
Anyone with information should contact Norfolk Police on 101.