The number of stop and searches under enhanced police powers has increased by 423 per cent in a year in London.
Metropolitan Police Deputy Commissioner Sir Steve House said searches under Section 60 of the Public Order Act 1994 leapt from 1,836 in 2017/18 to 9,599 in 2018/19.
The number of Section 60 orders authorised went up by 219 per cent in the same period, he told the London Assembly’s Police and Crime Committee on Tuesday.
The powers allow officers to stop and search anyone in a designated area for a limited time.
"I think we use it far more assertively than before, but I think it is an appropriate use," said Sir Steve.
"They are authorised either in anticipation of serious violence or immediately after serious violence."
He told committee members that knife injuries for under 25-year-olds are down nearly 20 per cent, although knife crime as a whole has remained flat.
But he said he did not want to appear "complacent" after a 33-year-old man died of his injuries two days after being stabbed in the leg in north London in the early hours of Saturday morning.
Earlier this year, home secretary Sajid Javid made it possible for thousands more police officers to authorise the enhanced stop and search activity after as part of efforts to tackle the knife crime crisis.
Under the changes, which initially apply to seven forces, the rank at which a Section 60 can be approved was lowered to inspector.
Gracie Bradley, policy and campaigns manager at human rights group Liberty, criticised the rise in the use of stop and search under Section 60 and called the figures "alarming".
"Race discrimination in stop and search is rising, and is at its worst under suspicionless powers," she said.
"Research shows there is no significant link between ethnicity and knife crime and that prohibited items are found across all ethnicities at similar rates.
"Stop and search without suspicion is a recipe for state abuse of power and does untold damage to communities' trust in fair policing.
"It is the antithesis of the targeted, considered and accountable policy interventions that we really need to address complex problems such as youth violence over the long term."