A Good Samaritan who helped a knife attack victim after a brawl on Dereham Road said the man had been 'walking into a death trap'.
Two men were stabbed after a fight among around a dozen men which broke out close to the Norwich Shopper.
No arrests have yet been made, and the two victims are making a full recovery in hospital.
It was around 1.30pm on Tuesday afternoon when a 31-year-old man sitting at a coffee shop on Dereham Road saw a group of men running in his direction carrying knives.
"One specifically had a massive knife, about the size of my arm. It looked like a machete," he said.
"There was more than 10 of them and they stopped at the bus stop before turning right and running down an little alley."
They were closely followed by another group of men, which included the two victims. One was bleeding from the face, the other was uninjured.
"They were at the bus stop wondering what to do," he said.
The second victim, who was uninjured at that point, took a friend's bike and went in pursuit of the group armed with knives, the man said.
"He had got to the park and that's where he was assaulted," said the witness. "He was unharmed at that point and went after the group with knives. It was like walking into a death-trap."
The second group returned to the bus stop, two of them wounded. The 31-year-old went to the aid of the man who had been stabbed to the torso.
"I applied pressure to his arm and tried to find out where the injury was to his stomach," he said. "He was in and out of consciousness, and I was just trying to keep him awake until the paramedics turned up and did their checks.
"It turned out he had been stabbed in the back and in the arm. The gash on his arm was about eight inches long and he had a stab wound on his back.
"We were just sitting there having coffee so it was totally unexpected."
Neighbours have said the area is "blighted" by street drinking and drug dealing.
A 57-year-old man, whose 83-year-old mother lives close to the Norwich Shopper, said she regularly had to "run the gauntlet" of street drinkers and drug dealers.
He said the problem had escalated over the last five years, with a "significant increase" in the last two years.
"I feel very angry about what has taken place - I believe this incident was inevitable given the level of anti-social behaviour in the area," he said.
"I am very worried for the welfare of my elderly mother and her friends who come to visit her - it must have been very frightening for anyone who witnessed the incident, and must increase the anxiety of those having to endure the anti social behaviour in the area on a daily basis."
He said he had reported incidents to the police and council but the response was often "erratic".
Police said the incident was "rare", and appealed for anyone with video footage to contact them.
Jane Watkin, chair of the Russell Street Residents Association, said drug dealing is getting "worse and worse" in the area.
"It is not getting any better because they can't stop it," she said. "It is so entrenched in the area and it's not just drugs any longer, it's the violence. It's people out to get their own patches.
"We don't want it to turn into a war between drug cartels.
"It sort of takes the polish off the new Goldsmith Street jewel in the crown because if you look at the surrounding areas they are all run down.
"It is really sad to see. The area has changed so much and it is losing a lot of its community. The public are also the victims here."
Norwich commander Supt Terry Lordan said the stabbing had been an "isolated incident" where the offender and victims were known to each other.
Police and council officers met with residents and business owners two weeks ago after complaints had been made around Distillery Square, he said.
"We had some complaints in the area so we met with seven residents and a number of shop owners to talk about drink and anti-social behaviour in the area," he said.
"We have gone to encourage people to report anything to us and we increased our foot patrols in the area a couple of weeks ago.
"A number of actions were agreed such as additional patrols and the council looking at cutting back some foliage, putting in additional lighting and signage."
He added stabbings are "very rare" and appealed for anyone with information come forward.
"This was in a public area and I know there will be numerous people who might have video in mobile phone or dashcam footage," he said.
"My plea would be for anyone who has captured any footage to please contact us so we can feed it into the investigation. There is no wider threat to the public and incidents of this kind are very rare.
"We take knife crime extremely seriously and I would urge anyone with any information to come forward.
"We will have reassurance patrols during the day and into the evening, and as we move forward the local beat manager will be looking at holding an engagement event in the area, so anyone with any concerns, please do come and speak with your local officer."
Anyone with information should contact Norwich CID on 101 quoting NC-05112019-214.
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