Teenage girl shot as she held her 11-month-old baby in her arms - The Guardian

A teenage girl shot in an apparent botched gangland attack in north-west London was cradling her 11-month-old baby when she was hit, police said.

Jessica Chrichlow, 18, suffered face, neck and chest injuries when a teenager armed with a shotgun fired into a crowd of young people.

Her infant son was "hugely fortunate" to escape injury, said detectives. But two sisters standing next to her, named locally as Alex, 19, and Sammy, 17, were injured. It is not believed the three victims were the intended targets.

Police are investigating whether the attack, on the Mozart estate in Queen's Park, is linked to escalating postcode gang violence in the area. In the 48 hours before Thursday evening's shooting, there had been three or four clashes believed to be gang-related, the Guardian has learned.

Detective Chief Inspector Mick Foote, leading the investigation, said: "There was a group of girls in the back garden and they were interacting with a large group of boys. It appears that a man has gone towards the crowd and discharged a single shot."

The gunman shouted "motherfuckers" as he fired, then fled to join three other youths, all with hoodies covering their faces and on bicycles. Police said the youths in the large group appeared aware something was going to happen because they ran off just before the shot was fired.

Jessica's mother, Isabel, said her daughter, who is in a "stable condition", was undergoing surgery on her face, neck and chest. "I want everyone to know that this boy has put a bullet in her heart. She was holding her baby in her arms. He was covered in blood. My daughter was on the ground bleeding," she said.

The 17-year-old girl was discharged from hospital on Friday and her sister was said to be in a "stable condition".

The investigation is being led by Trident detectives, who combat gun crime in the black community.

The Mozart estate, once a 1970s concrete jungle nicknamed "crack city", has seen an increase in serious youth violence in the past 18 months. On the edge of Westminster, Kensington and Chelsea, and Brent boroughs, it has seen postcode wars break out between rival gangs; in particular those from South Kilburn and Ladbroke Grove are said to have targeted Mozart.

Fabian Sharp, community co-ordinator for the Paddington Development Trust, said stabbings, muggings, abductions and kidnappings were frequent as certain youths tried to make it a no-go area. "There is a group of young people who have decided one of the best strategies they can employ to try and keep themselves safe is to 'big up' the reputation, the notoriety, that the Mozart estate once had," he said.

As part of a £30m refurbishment programme 15 years ago, parts of the estate were demolished and rebuilt in a bid to tackle crime. "It was a quick win, £30m, knock it down, rebuild it, paint it, make it look nice and pretend the problems are over," said Sharp. "But they failed to tackle the social issues."

A new generation of young people were now "using whatever techniques they can think of to try and protect themselves".

"So whether that's restoring the notorious reputation of Mozart, or making it a no-go for people from outside, or hanging out together in a group – call it gangs if you like – it makes them feel safer. It's frightening for a kid growing up, I think, anywhere in London, and here's no different."

Westminster city council said serious youth violence incidents in the borough saw a 49% increase rising from 197 to 309 incidents in 2010-11. There were 133 incidents for the first few months of 2011-12.

Earlier this month the council approved a £1.5m plan to tackle the problem, with measures including a gang information desk, to monitor social network sites including Facebook, YouTube and BlackBerry Messenger, and a dedicated gang worker. It intends to establish a cross-border gang mediation programme with neighbouring Kensington and Chelsea and Brent boroughs. It is to lobby for extra government funding for such projects at the Conservative party conference in Manchester next week.

Karen Buck, Labour MP for Westminster North, who visited the Mozart estate after the shooting, said recent clashes had included one boy being stabbed 13 times who was "very lucky to be alive", and another "kicked into a coma". Though police had not established if the shooting was gang-related, she said: "The perception is that it's part of postcode violence that's been getting progressively worse over the last couple of years."

Calling for "high-level cross-borough policing", she said: "There's a sense gangs are a Hackney or Lambeth problem. And people don't quite believe leafy Westminster and Kensington have this problem. And they do".

Stop-start funding for youth service projects was "too inconsistent", she said. "There is good work being done, and we know a lot of the answers to this. But it's on far too small a scale."