Mean streets: Friday night, Saturday morning: a portrait of anti-social Britain

You wouldn't know there was a problem in the heart of upmarket Upper Norwood. The restaurant-lined streets of Gipsy Hill and the large English Heritage-protected Victorian and Georgian mansions – some of the former still with their original Arts and Crafts detailing – seem an unlikely place for murder, stabbings, shootings and robberies.

Yet last week 23-year-old Evren Anil was in the passenger seat of his sister's car as she pulled up at traffic lights at the junction with Gipsy Road. Two black teenagers walked past and threw a Lion bar into the car. Anil got out to confront them, the boys produced a knife and hit him. He fell to the floor and smashed his head on the pavement, dying of his injuries a few days later.

Related articles

• Joan Smith: I'd rather confront a terrorist than a litter lout
• Search the news archive for more stories

His murder followed that of Gary Newlove, a 47-year-old father-of-three who died after being attacked by a gang of drunken teenagers in Warrington last Sunday.

Mr Newlove's death prompted the Chief Constable of Cheshire, Peter Fahy, to call for the drinking age to be raised to 21 and for children to be put into care if parents cannot curb their under-age alcohol consumption.

Once again the spotlight has fallen on Britain's so-called "feral youth". Nestling amid the big houses of Gipsy Hill sits the Central Hill estate. The concrete sprawl is built on the side of the hill and commands stunning views of the metropolis.It was into this rabbit warren of alleys and staircases that two young men fled after the attack on Mr Anil.

On the wall next to a garage bay are two sets of seemingly innocuous initials, however: PDC and OC, the Poverty Driven Children and the Organised Criminals, two of London's most notorious gangs.

Hailing from Brixton, both gangs are considered enemies of the local gang known as the Gypset. "There are about 70 of them," said one 16-year-old girl who asked not to be named, referring to the Gypset. "They don't all hang around together but you see them here, there and everywhere. They claim to be guarding the area. They won't let anyone from outside come in: they see them as trespassers."

A shopkeeper, who also didn't want to be named, complained that gangs of kids from the estate caused all sorts of trouble.

"This area is not safe," he said. "Teenagers from the estate come in here and bother customers. They come in gangs of five or six and just take things – whatever they can get, money from the till, stock. They throw food outside. They are aged from 13 to about 22. They will stand in the doorway and not let anyone in or out. They think they can do anything."

On Friday night the estate was quiet. Mature trees and the efforts of residents make it far from ugly. But not all the lights are working. One alley staircase is pitch black.

In a quiet corner of the Central Hill estate on a set of concrete steps, a dozen teenagers sit around in the semi-darkness, smoking and drinking. Empty beer cans and bottles are scattered around. As a reporter and photographer from The Independent on Sunday approach two of them immediately get up and slip away into the shadows. A youth in a white T-shirt, baseball cap on his head, sits on the top step.

A girl sits beside him and they share a single set of earphones from an iPod, their heads slowly nodding in time to music only they can hear.

He waves his hand dismissively at the idea of speaking to a journalist. "Nah, you're all right, mate," is all he will say.

On Thursday a 24-year-old man, his body riddled with bullets, was dumped in the ambulance bay of the local hospital, King's College, by people who sped off as soon as they had tipped him out of the car. The stabbed and shot are regularly left outside the hospital. Less seriously wounded victims walk into reception and queue up with everyone else. "That tends to be gang-related stuff. It's regular enough for us not to get overly excited when it happens," said Briony Sloper, operational manager for Kings' emergency department, where the staff have a hotline to the police.

"We're so used to stabbings, gunshots, drugs, people coming in with weapons, that it's something that the team are all well versed in. It's not unusual to find a gun tucked under something, and we found a machete tucked down someone's bottom cheeks not long ago."

Usually the department sees five victims of serious violence a week – one shooting, three stabbings and a nasty beating. A senior nurse said that not only did street violence appear to have risen dramatically over the past two years, but it was getting more vicious.

A specialist registrar who had treated the previous night's shooting victim, who is in a stable condition, said: "I was in a hospital in north London, where in six months I saw three or four stabbings. I started here on 1 August and have seen two with gunshot wounds and four or five stabbings. And you see a lot of kids here: I saw a 14-year-old who'd been stabbed."

Many of the problems here and further afield are linked to under-age drinking. Last week Newcastle Crown Court heart how 29-year-old Lee Harris was kicked in the head 30 times and beaten into a coma with a brick by a gang of teenagers who were furious that he refused to buy them alcohol.

Jack Johnson, a 26-year-old football agent from the Central Hill estate, agreed that the problem was getting worse and said he was careful to avoid any form of confrontation.

"Do I feel scared? Am I intimidated? Of course I am. Every time I get home I feel happy because I'm still alive," he said.

Additional reporting by Sadie Gray

The victim: Evren Anil faced up two to youths and paid with his life

Five men arrested in connection with the death of Evren Anil have been released on bail. Police are still piecing together what happened when Mr Anil, 23, was attacked at traffic lights in Gypsy Hill in south London on 5 August. Witnesses have been urged to come forward and police are looking for two teenagers whom Mr Anil confronted after a half-eaten chocolate bar was thrown into his sister's car. Mr Anil died in hospital on Monday, eight days after the attack, from a head injury.