They are, according to Lee Jasper, the Mayor of London's senior adviser on policing, "the biggest criminal phenomenon" he has ever witnessed. Sworn to bring a criminal jihad to Britain, they don't just do law-breaking, they do it, apparently, with a militant Islamic vengeance. If their advance publicity is to be believed, they make the Yardies look like the Women's Institute.
Can all this be true? Is there really a gang at large in the capital dedicated to combining organised crime and religious mania, and funnelling the proceeds to terrorists overseas? Or is this another mob of urban hoodlums who have merely adopted jihad as a blood-soaked flag of convenience and intimidation? These are not the kind of questions that can be answered in the reading rooms of the British Library. The streets are the place.
When you go looking for the Muslim Boys, you have a hunch that the nervous wait for them to turn up may not be the worst bit. And you're right.
Myatts Fields North Estate, Brixton, is not, for the uninitiated, exactly Henley-on-Thames. We've been told that they meet here at around 4.30pm before they go off to do what they do best, committing serious organised crime.
A black, two-door P-reg hatchback slips into one of the parking bays. Sitting in the back are three young lads. A few minutes later a teenager in a red-and-grey hoodie emerges from one of the back passages and greets the three. Then, using a brick, he smashes the car's back windscreen. The car is slammed into reverse and driven off. When the car brakes, the glass catapults on to the back seat.
The rest of the group takes this as a signal to come out, and about 20 Afro-Caribbean youths aged 15-25 gather by the communal bin area. I go up to the group and ask them why the gang has adopted the name the Muslim Boys.
"Na, na, Islam is peace so how can there be a gang called the Muslim Boys?" says a 16-year-old teenager with a large scar on his chin, who doesn't want to give me his name. "Go and look at the Koran and you'll see what Islam's about. It's not about some gang," he says.
He admits they are part of a gang but says that they just happen to be Muslim.
"If some white guy came here shooting, then would you go and say he was a Catholic shooter, would yer?" he explains.
I ask him if wants to talk further. "Na mate, to be honest we're only talking to you 'cause you caught us at the right time. We're about to leave." They tell me that I should do the same.
The Muslim Boys have been linked to dozens of murders, shootings and other serious offences in south London in the past 15 months. By some estimates, they are said to number 200-250. The Metropolitan Police say that there is a hardcore group made up of only 20-25 members, but recognise that other gangs have taken the name of the Muslim Boys "in order to gain street credibility".
During recent weeks, the Metropolitan Police say have arrested around 20 members of the gang, including "one of the lead individuals".
And last week, 19-year-old Zirtash Khan, a suspected member of the group, was given a 22-year prison sentence for the attempted murder of a police officer in Bromley last December. During the arrests the police also seized Mach 10 submachine guns, something considered to be heavy weaponry for any London gang.
But what makes them unique among London gangs is their discipline and strong sense of identity developed from their own version of Islam. Mr Jasper says that as soon as the group formed around January 2004, he kept receiving consistent reports from members of the black community in Brixton that the gang was not just very well organised but that they would also go around and forcibly convert the biggest and brightest of the south-east London criminal fraternity to take up what he terms as a "criminal jihad".
"Since January 2004, the Metropolitan Police have been aware of consistent reports coming from the black community that there was the development of a group of boys who converted to Islam in prison and then taken up a criminal jihad," he says.
The most infamous case of forcible conversion was that of Adrian Marriot, who was bullied and hounded into converting and then killed by several shots to the head when he refused.
Mr Jasper says that these "devout criminals" make their money from robbing other gangs and pimps, but that when the police raid hideouts they find only a "mattress and the Koran".
He says that the Muslim Boys have been making thousands of pounds every day and he has been worried for some time about where the money is going. His fears have only been heightened since the lead suspects of the 21 July came from Stockwell, just a few minutes away from the Myatts Fields Estate. "They're making thousands, but where's it going?" he asks.
Max, a resident on the Myatts Fields Estate and a Muslim himself, has grown up alongside a number of the Muslim Boys. When I ask him where they spendthe money, he replies: "Footlocker [the sportswear shop]".
He says after press reports about the gang last year, and what he calls the "demonisation" of Islam by the media, the gang's image was hyped and other youths started to call themselves the Muslim Boys. He says this led to more conversions to this strange brand of gangster Islam.
Max, who studies film production in Vauxhall, says that most of the original group converted while in prison, specifically in Feltham Young Offenders' Institute. He says that for the Muslim Boys, Islam is just another form of shaping a sense of identity and that forced conversions should not be that surprising: "It's just like any other form of bullying."
This linking of Islam with serious crime is something the Brixton Mosque has worked to defeat. A number of the Muslim Boys used to pray at the Mosque until tensions were heightened after the death of Adrian Marriot. The imam at the mosque, Imam Omar, had to explain to the family that this was nothing to do with real Islam or with the mosque.
"It is something that is prohibited in Islam and as a Muslim one should try to desisit in these activities," says the imam.
However, Max says that despite being told not to attend by the mosque's management, the Muslim Boys still pray at a number of other mosques around the estate and in Stockwell.
The police insist they are making headway. The Met's Operation Trident is committed to tackling gun crime within London's black communities, and closely monitors the activities of a number of gangs involved in this type of crime. Its head, Det Ch Supt John Coles, says: "Trident has had considerable success in targeting these people. We have arrested most of the hardcore of this gang.
"In the boroughs where the so-called Muslim Boys operate, gun crime is actually down. In Lambeth, for example, gun crime is down by 24 per cent, and the detection rate in the borough is currently at 29 per cent.
"Overall in London gun crime is down by 10 per cent. This downturn has been sustained over two years. We hope to drive it down further by working closely with the community, and mounting proactive operations."Reuse content