A police team on the front-line of London's knife crime battle has described finding more weapons and more gangs on the streets as a crimewave grips the capital.
The Metropolitan Police's Territorial Support Group (TSG) has been on-hand during a spate of attacks in the last week.
Sergeant Paul Perversi said stop-and-search efforts on members of the public had been increasingly uncovering weapons.
He added that social media was causing disputes to quickly escalate into violence while also increasing hostility to the controversial police tactic.
It came as the unit patrolled the streets of east London on a busy Friday night, responding to calls including a man armed with a knife in the street and an attempted robbery by a masked gang.
The 18-year veteran of the force told the Press Association: "With what's happening in the last week, we are seeing more and more groups of youths going around and congregating at the hotspots. We will stop them, we have been utilising that power - but we have to use it proportionally.
"Personally on our beat we are finding more weapons. That could be to do with demographics or the area.
"Between us all we have come across victims of knife crime - it is horrendous when you see a victim with a knife wound, it makes you think."
Reflecting on the sharp rise in knife violence, he added: "They put a video on YouTube and then they get stabbed."
But despite the surging levels of violence, the unit does not let statistics cloud its judgment on who to search, the sergeant claimed.
"We are not a figure-run sort of department," he said.
The popularity of smartphones and social media has "massively" encouraged more people to challenge officers during stop-and-searches, he continued.
Many stop and film the process before uploading it online.
"I would say it happens more often than not.
"If you stop two people out of 10, you will have five people who get their phone out. Then you go and search on YouTube and I'm there."
TSG travels between boroughs, supporting local teams and providing back-up to major incidents.
Stop-and-search is also a key component of the unit's work, a tool the sergeant said was vital to combating crime.
It has been criticised as a policing method for disproportionately targeting poorer areas and ethic minority groups.
"On the TSG it's bread-and-butter policing. It is a valid tactic but very quickly it can escalate into a violent confrontation.
"I would like people to let us do our jobs without the hindrance. People shout at us and I cannot shout back because I will end up on YouTube."
His team stopped four groups while out on a drive-around with the press, none of whom faced any further action.
All were offered an explanation for why they were stopped and a written notice documenting the incident.