Nearly a thousand young people were shot or stabbed in London last year, according to shock new figures released yesterday.

The statistics from London’s ambulance service reveal that in 2013 paramedics were called to treat 973 victims under the age of 25 suffering a gun or knife wound. Most of the injuries — 850 — were caused by knives, with 123 young people being shot. The majority of cases are believed to be linked to gangs.

The figures were released as mayor Boris Johnson hosted a Gangs Summit at City Hall yesterday on the challenges of tackling gang crime in world  cities.

The latest figures, contained in a report on the mayor’s gangs strategy, underline the scale of gang violence in the capital. Police also admit the figures may not reflect the full extent of the problem with many less serious injuries caused by knives and even guns going unreported by gang members.

But police also say they have cut gang crime by 23% in the last year and claim the number of gangs and gang members has fallen in the past two years.

The latest intelligence estimates there are 3,495 gang members in London —compared to 4,800 in February 2012 — and 224 gangs, down from 250.

Speaking yesterday, Mayor Boris Johnson said: “London has turned a corner with gang crime and serious youth violence down in the capital but I recognise we have more to do. This is about taking a nose-to-tail approach — not just looking at an endgame, with young people already involved in criminality and the criminal justice system.

“It is working to ensure they are not drawn into gang culture in the first place and make it easier to leave when they are already involved.”

Statistics released yesterday show a total of 183 gangs were linked to more than one offence in the past 12 months while 58 “particularly active” gangs accounted for two-thirds of gang crime in London.

The majority of gang members on the Met’s “matrix database” are aged between 17 and 23 and almost all are male — just 40 women are on the list.

The report also highlights how 61% of all gang members have been victims of ordinary crime, around half of them victims of violence.

A study by the mayor’s office for policing and crime highlighted a lack of “exit services” for gang members and said more should be done to intervene in schools and among families to prevent young people joining gangs.

The report also warns that gangs are becoming less territorial and “more concerned with income generation, such as the sale of drugs.”

The mayor pledged to spend £3mn funding 25 gangs projects in London over the next four years.