They wear mini-skirts or tight pants, scanty tops and long fashion boots. Their faces are shiny with cheap make-up. They are, all of them, girls aged between 13 and 16. They are ready for a night's work.
They often pop in to see Mohammed, but not just to buy sweets or teenage fashion mags or even the odd illicit packet of cigarettes. Theirs is a more practical purchase. "Got any condoms?" they say, brittle young faces brazen behind the eye-liner and lip gloss.
"Some of them are really good-looking lasses," says Mohammed. "I ask them: 'Why? Why do you do this?' Then one of them will show me a wad of money. Up to pounds 400 in cash. That was one girl's answer. I happen to know that she's feeding her boyfriend's crack habit."
In the small hours of the next morning, long after Mohammed has shut up shop, and a few hundred yards further down the road, Paul Stokes will be trying to sleep in the flat over the pub he manages. The girls are still out and about, laughing and shouting and trawling for trade.
"I can hear car doors slamming and horns sounding until three o'clock in the morning," he says. "I look through the window and see the girls spread out along the street. Two of them, I know, are no more than 12 or 13. Their pimps ride round on push bikes, keeping an eye out for the police and giving a warning when they're on their way. The girls scatter. But they're back the next night and the next..."
These are not scenes from the stews of some Third World city. This is the borough of Middlesbrough, principal provincial town of post-industrial Teesside.
This week Home Office minister Timothy Kirkhope will lead a sizeable band of British civil servants and professional carers to an international conference in Stockholm. The subject: worldwide commercial sexual exploitation of children.
The minister will tell delegates that we in Britain are ready to join wholeheartedly in the worldwide battle against "sex tourism" - that trade in child prostitutes notoriously well-established in Thailand and the Philippines - an industry for which British males are major customers: by some reports, third in the Western world's league of offenders.
Mr Kirkhope will also say that here in Britain we have developed, over the past few years, new enlightened, "multi-agency" procedures to deal with our home-grown child sex industry.
So, if everything is under control in Britain, why did Barnardo's, the children's charity, raise the alarm last week, revealing in such stark and lurid terms the plight of young girls in Bradford, some as young as 12, who have been lured into prostitution? And worse - why were other social workers able to claim that this is now a problem in all major cities in Britain?
It is, social workers believe, another landmark on the long trek from the Cleveland child sex abuse scandal which burst messily into the headlines nine years ago and delivered a seismic shock to our smug assumptions about the inviolability of our children.
Rachel O'Brien of the Children's Society believes child prostitution in Britain is on the increase. "To a certain extent it's something about which we've been in denial," she says. "And on another level it seems to be saying something about the state of British masculinity, when men deliberately seek out under-age girls for sexual gratification."
Last year the Children's Society published a report, The Game's Up, calling for prostitution to be decriminalised where those under the age of 18 were involved. Prostitution for these youngsters, it said, was last-ditch survival strategy; punishing them was cruel and pointless. They were victims of adult failure - mostly runaways, those who had fled home or residential care; children full of self-loathing and rage against the world, whose formative experiences had often been meted out by alcoholic, abusing parents or the under-paid, under-trained bullies often to be found in children's homes.
Home Office figures, according to the society, appeared to indicate that the number of 17-year-olds being cautioned and convicted for street offences had fallen; whereas the statistics relating to younger children, especially girls, revealed an increase. In 1989 only 31 children aged 10-16 in England and Wales had been convicted for soliciting offences. Five years later the figure had increased to 52. Similarly, cautions for child prostitution had increased 50 per cent. These figures were only the visible, statistical tip of a real-life iceberg.
The record, none the less, showed that, over four years, 13- and 14-year- old girls were being cautioned and sometimes convicted in increasing numbers.
Teenage girls, like adult women prostitutes, are generally given two street cautions under the Street Offences Act 1959. If they are subsequently stopped by police on the street they are usually charged under Section 1 of the Act with being "a common prostitute loitering or soliciting in a street or public place for the purposes of prostitution". There are recorded instances of this happening to 14-year-old girls.
The society's message was uncompromising. More young girls were going on the street. But they shouldn't be so labelled. They were victims. "Whether it takes place on the street in this country or is classed as sexual tourism abroad it amounts to the same thing," insists Rachel O'Brien. "It's about adults abusing or profiting from the sexual abuse of vulnerable children."
Last week Barnardo's revealed the results of its year-long project on the streets of Bradford, West Yorkshire, set up to help child prostitutes with counselling, medical treatment and housing advice. The message was the same. The girls are victims - not a social disease to be wiped out by law and order institutions.
The Barnado's report revealed insights into lives we would rather not know about. The girls are cajoled into the sex trade by predatory pimps who shower them with gifts, the good life and a gruesome, ersatz version of that one commodity they have never had - human affection. These girls are the loveless and rejected, runaways from residential homes and abusing parents. For their pimps they will eventually do anything - out of "love". They will go on the streets at all hours. In return they are often beaten, raped and tortured.
Worse still, said Barnardo's, there is a growing appetite among the "clients" for ever younger girls; kerb crawlers asking 14-year-olds where they can find 11-year-olds. The younger the girl the less chance of contracting HIV/Aids, they say. Indeed, this has long been the twisted logic of European males who flock to the girly bars of Bangkok. The younger the girl, they say, the cleaner she will be.
Detective Chief Inspector Don Harrington, head of child protection for the West Riding police says the situation is horrifying. "These girls are literally besotted with their pimps. They don't go on the street for money, that's all handed over to these alleged 'boyfriends'. These girls offer their bodies for sex with strangers to preserve the relationships with the pimps.
"We are at a turning point. We must treat the girls as victims, their clients as sex offenders and child abusers, and pimps as party to a conspiracy to encourage child abuse. In other words crank up the seriousness of their respective offences."
Superintendent Mike Hoskins of the Metropolitan Police Vice Unit would agree - but points to the gulf that yawns between ideal practice and actual, on- the-ground processes of law enforcement. His officers know the trade in child prostitution is well organised. Teams of pimps travel south from the North and Midlands with what the police call "posses" of young girls. Theirs is an itinerant life - moving on from town to town; Nottingham to Norwich to London to Plymouth, living in guest houses, travelling by train.
"They're always one step ahead of us," he says. "Normal police procedure is to observe the activities of prostitutes, their clients and the pimps so that officers can go into court and give evidence. We can't do this in the case of young, under-age girls. We have to get them off the street as soon as we see them. The public would be rightly horrified if they thought we just sat there and watched them being exploited."
The girls are taken into a police station and - occasionally - one or two might give evidence against their pimps, and actually sign a written statement. The police would then like to hand the girls over to social services for their own safety. But the social services have neither the power nor resources to provide this protection, they say.
"The net result," says Supt Hoskins, "is that we have to release the girls, who go back and tell their pimps what's happened. The girls appear at the station next day to withdraw their statement. Then they and the pimps, duly forewarned, move on or disappear. It's soul-destroying for my officers."
Rachel O'Brien concedes this can be the case. "The trouble is," she says,"that social services are conditioned to intervening only in cases where a teenage girl has been abused in a familial environment, say by a father or uncle or by a teacher at the school camp. In these circumstances it would be treated as a matter of the first priority to provide a place of safety for such an abused child. Girls involved in prostitution are often not seen in the same light and thus are not given the same priority. But if there was a general and concerted will on the part of the various agencies to provide a secure refuge, it could be done."
Media coverage of teenage prostitution is not helping, says O'Brien, sometimes merely feeding a salacious public hunger with images of sickly glitz.
"We should not lose sight of the fact that we're talking about children who take to prostitution not for money or glamour but because it's a last resort. Of course many of them willingly return to prostitution even after passing through the hands of the police. They have endured such painful, loveless lives that going back on the street is preferable to being put back into care where they've been bullied, or being sent back to parents who don't love or want them, may even be abusing them.
"We have got to offer these children a realistic exit from life on the street. We must not criminalise them. A child under 16, the age of consent, cannot in law agree to a sexual act with an adult, yet in this country we have convicted 12-year-old girls of prostitution. It's absurd.
"We are not talking here about prostitution; this is sexual exploitation and abuse of children."
Police in West Yorkshire and London say they have adopted a more enlightened approach. Girls under 16 are rarely if ever prosecuted. Sgt Brian Donegan of the Met's Vice Unit says: "We are not interested in putting the girls in court, it's the pimps we really want to nail."
Back in Middlesbrough, Mohammed Affy, his neighbours and fellow shopkeepers would like to see the girls leave their streets. He feels sorry for them but knows their nightly presence makes others angry and scared.
"We are plagued by the kerb crawlers," he says, "people coming in from out of town because they know the young girls are here. People are putting their houses up for sale, desperate to get away. And yet the police do nothing."
Not quite true.
Chief Inspector John Tough has announced his own shock tactics which he hopes will clear Middlesbrough's city centre streets of most prostitutes, young or old. He is focusing not on the girls but on their clients.
"I have made it plain that any man found kerb crawling will be summonsed and taken to court. We are setting up a new operation to clear the streets by taking away demand, not attacking the source of supply. Any man taken to court can be sure his wife will know what he has been up to, as will his friends and his employer. It may sound crude but I hope it will be effective."
This week in Stockholm, Timothy Kirkhope will, he says, be adopting a militant stance: "I'm not going there to drink tea and smile at people. As far as the British government is concerned one child prostitute is one too many, in this country or abroad."
Two days after Barnardo's revelations the Association of Chief Police Officers, the Association of Directors of Social Services and the Children's Society issued a joint statement announcing a review of current police practice which henceforth will emphasise protecting child prostitutes - and pursuing the adults who abuse and exploit.
But Mr Kirkhope still refuses to countenance the decriminalisation of child prostitution.
"In the few, very few, really serious cases involving older girls, the 15- or 16-year-olds who have a history of persistent offending, there will be prosecutions," he says. "This decision has been taken after considering all the best advice. The feeling is that to decriminalise completely would be to encourage some girls to take up the activity."