The four black teenagers ripping open crisp and cigarette packets after a visit to an off-licence were all agreed about their opinion of the police.

“They are f****** harassing bastards,” shouted one. “A disgrace, man,” screamed another, as they wheeled their mountain bikes with contemptuous aplomb into busy traffic racing along Alexandra Road in Moss Side, Manchester.

It is not surprising that they showed such disdain. It is highly likely that their activities have been subjected to some of the most intensive policing seen in Britain.

Operation Cougar, designed to take violent gangs and their weapons — particularly guns — off the streets, has been running since last February. The Gooch and Doddington gangs — the city’s most entrenched rivals, largely comprising black youths, who eye each other across the four-lane highway — have been feeling the heat.

Peter Fahy, the Chief Constable of Greater Manchester, invited Jacqui Smith, the Home Secretary, to Manchester yesterday to praise what police say has been a ground-breaking operation. Mr Fahy said that there had not been a single firearms homicide in Greater Manchester in the past year — for the first time in more than a decade. The number of gang-related firearms discharges had fallen by 92 per cent in the same time.

Broadfield Park, the scruffy parkland where Jessie James, 15, was ambushed and shot because he was probably identified wrongly as a rival gang member, is among the most fiercely protected gangland turf in the country.But during the summer the gangs — who deal in drugs, patrol their fiefdoms with threats backed up by guns or simply gather in intimidatory numbers — were forced to realise that they faced a new kind of policing.

Officers from Xcalibre, the unit that targets gang culture, would descend in overwhelming numbers without warning to arrest or “get in the face” of youths pinpointed by plain-clothed spotters patrolling in unmarked cars.

Yesterday Broadfield Park was peaceful enough for walkers to stroll there with their dogs. A Manchester Evening News poster outside a newsagent’s read: “Police winning the war on gangs.” Few residents appeared willing to agree that the war was over but community leaders have been happy to talk about a lifting of tension.

In the early 1990s it was the killing of Benji Stanley, 14, caught in the crossfire as he queued for a takeaway, that led to the city’s “Gunchester” reputation and prompted a public outcry that produced police action.

More than a decade later, it was the image of Jessie James’s grieving mother, Barbara Reid, who told her son’s inquest that he was cut down by automatic gunfire because he refused to choose a gang, that encouraged the police to go on the offensive.

Their action was given urgency by the murder of Halton McCollin, 20, a promising footballer who was shot in the head in a takeaway in Stretford. The intended victim was believed to be a member of the Doddington gang.

A week later the gang threat was deemed “critical” when Louis Braithwaite, 16, was shot in a betting shop in Withington, another inner-city area.

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