A teenage boy has been arrested after police said he tried to slash another pupil’s face with a meat cleaver.
The 14-year-old was taken into custody after the dispute, which took place in school.
Police in Brent shared an image of the huge weapon, which appeared to be around 14cm (5.5in) in length.
Police said no further information was immediately available.
Knife crime is on the rise in the UK, with at least 40 people suspected to have been deliberately stabbed to death since the start of the year.
Several of the victims have been teenagers.
Last week, after coming under intense pressure to boost police resources, the chancellor announced an extra £100m emergency funding package to allow police to mount more operations against violent crime.
Officers tackling violent crime told Sky News this week that police need sustainable, longer term funding to ensure the knife crime crisis is properly dealt with.
The chairman of the Police Federation, John Apter, told Sky News that this amount was “nowhere near enough” to end the crisis.
He said: “This is a drop in the ocean when it comes to money that’s not only been stripped from policing, but other budgets, the social services budget, the education budget, and this is dealing with a crisis so yes, it’s going to help a little bit, but it’s not enough.”
Officer numbers have fallen by almost 20,000 since 2010.
In addition, the National Audit Office said that total funding for forces in England and Wales was reduced by 19% in real terms from 2010-11 to 2018-19.
Home Secretary Sajid Javid said the funding, which includes £80m of new money from Treasury coffers, will allow forces to quickly crack down on knife crime in the areas where it is most prevalent.
Mayor of London Sadiq Khan welcomed the funding, which he described as “limited action”, but said it was a “drop in the ocean” compared with “huge cuts” to police and preventative services.