Behind them, in a row of revamped railway arches, 100 or so of the area’s most violent and disaffected teenagers gather each night to make friends, cakes and music. Sounds unlikely?

The organiser of this “teenage mental health club”, Camila Batmanghelidjh,thinks so too. But that is what is happening here, under a railway line off the Camberwell Road.

The club - popularly known as The Arches - was originally intended for primary school children. Camila Batmanghelidjh’s organisation, Kids Company, was counselling children in local primaries, and wanted to offer them a place other than the streets to hang out when school finished. But late last year, following publicity generated by a children’s art exhibition put on by Kids Company, older children - mainly boys aged 13 to 17 - suddenly descended in large numbers. Camila Batmanghelidjh and staff began offering jungle music, drama and food to the teenagers. “It was hell,” she says. “They threw the food on the floor, and at each other. They had knives, and these peculiar-looking screwdrivers that they were tearing into the walls and soft furnishings with. The police came and said we had some of the most criminal children in the borough on site. I was very gentle, very calm. Standing there almost like a hotelier saying ‘please’. I think that’s what worked.”

Three months later, after some ugly incidents, the theft of the club computer and intensive shuttle diplomacy with local residents, the club had become established. It is now an oasis in a desert; the ugliness and aggression of the surrounding streets are banished, and only here would one think to call disused railway arches “cosy”. The club now occupies four of them, brightly painted with the help of the children and split into a myriad of small, cushioned cabins for counselling or sleeping, a library, a “board game saloon”, a kitchen and a sports and music area. The children, often scruffily dressed and dirty, lay down both their weapons and their defensive attitudes at the door. “It’s been the most profound thing,” says Camila Batmanghelidjh, “to see these really hard boys show their tenderness and begin to trust you. Behind every one of these thugs is a horrible life history.”

Teenage violence has been front-page news recently, following a spate of stabbings in secondary schools. Much of the problem appears to be linked to gang membership. Nathan Brown, leader of a Triad offshoot called the Golden Snakes, was jailed for life last month for the murder of 14-year-old Carl Rickard. Kidbrooke School, where Carl was a pupil and outside which he was fatally stabbed, is a few miles away from the club, bordering on the gentler suburbs. In this part of south London, gangs are a fact of life for these children from primary school onwards, regardless of whether they join one. Some gangs recruit from a very early age - hence the local “Young Young Peckham Knife Boys”, who are to the Peckham Knife Boys what the Beavers are to the Scouts. Five or six opposing gangs are represented in the club, but hostilities are suspended on site.

To Camila Batmanghelidjh, the appeal of gang membership to these children - many of whom have more or less brought themselves up - is obvious. “It’s a substitute family,” she says. “They need to know that there’s a group of people looking out for them.” Some of the children are from startlingly large families - one boy has about 20 siblings and half-siblings - but their home lives are fragmented and buffeted by poverty, drug addiction, mental illness and crime. “There’s enormous neglect, and disconnection with the parents,” says Camila.

Adrian, 14, is a charming, wary boy who makes only fleeting eye contact from under his baseball cap. The oldest of six children, he claims he was adopted by the Triads as a 10-year-old after they saw him fighting. “I got paid - #163;200 sometimes - just for being with them, doing stuff. At first I thought it was exciting. You see the older ones, how much clothes, money and cars they’ve got. If you really want to be with the gang, you’ll do just about anything.”

Adrian has had bottles broken over his head and done a lot of fighting on behalf of his substitute family. He says he has seen friends stabbed, imprisoned and dead. He recently decided to leave the gang. “I went to one of the top people and said I was leaving because I wanted to study.” He is excluded from school, and says he wants to be an architect. He comes to the club every day and is in charge of the library.

If gang membership offers one form of belonging, this unorthodox club offers another. The children clearly feel at ease here, and proud of their place. Staff - a mixture of local people and about 30 counsellors, and mainly working part-time - offer practical help such as hot food, which is available every day, when the doors are open from 4.30 to 6.30pm.

The counselling is directed at helping children make life choices, and some of the youths bring their mums along for help. Susan Francis, a 33-year-old struggling alone with teenage twins and a baby, is one of them.“This place has given me a little spirit,” she says. “The people are really nice and you can talk to someone if you’re feeling down. It’s more homely than at home.”

Children aged 10 upwards are allocated jobs, ranging from sweeping floors to tidying toys, for which they are awarded points. At the end of the month, the points are translated into money; no cash is handed over but staff accompany children to buy shoes, bus passes, school uniform, bags and clothes. They earn on average around #163;35 per month. “It would be a lot if it was just spare pocket money, but it’s not, it’s life money,” says Camila Batmangheli djh. It was the children’s committee that decided cleaning lavatories and washing up would be the best-paid jobs. The committee also decides how long children who break the rules - no drugs, weapons, smoking, spitting, fighting - should be excluded for.

Camila Batmanghelidjh, who has to fund-raise ceaselessly to keep the project going, would like other boroughs to replicate it. She says the club - which has grown “organically” out of what the youths want - is part of a “socially intelligent” approach to mental health that is cheaper and more effective than traditional approaches to children with emotional and behavioural difficulties.

“None of these young people will attend clinics,” she says. “They do not always know how to ask for help, and will take a long time to trust adults.Psychiatric and social service appointments once a week or twice a month will do nothing to address their needs. They need the consistent care of a community environment. ”

The Kids Company is a charity that relies on donations from individuals, corporations and public sector organisations. It was set up in 1996 to bring not only counselling but also activities such as art, music, drama and football to deprived children who, says the charity’s founder Camila Batmanghelidjh, are slipping through the mental health net. For

more details contact Kids Company, co 40 Barforth Road, Nunhead, London SE15 3PS