Scotland Yard Commissioner Cressida Dick took part in the raids across west and south west London, targeting a notorious gang whose trade in drugs is, according to police, helping fuel violence.
The raids are the culmination of several months of covert work by members of the Metropolitan Police’s Trident gang unit.
More than 200 officers took part, including teams from the Met’s firearms command and Territorial Support Group officers.
Cressida Dick said the operation underlined the determination of her officers to go after criminals involved in serious crime and violence.
Dozens of police vehicles left their base in north west London around 2am, heading for eight addresses, which police said were connected to senior members of the “MDP” gang, a long established criminal network which has been linked to several murders.
At one property in south west London, officers found a sub-machine gun, a handgun, a large quantity of what they believe to be class-A drugs and a large amount of money.
A suspect from the property was stopped and arrested a short time later in his car in Acton, West London.
Detective Sergeant Paul Chapman from Trident said: “On initial inspection they look like they found what appears to be a Scorpion sub-machine gun and a large quantity of class-A drugs which are all linked within the gang we are targeting this evening.”
A total of nine people were arrested in the raids and held on charges including conspiracy to supply drugs and possession of firearms.
One of those arrested was just 14 years old. Police recovered a large amount of suspected class-A drugs from the boy’s home.
Speaking to Sky News, Scotland Yard’s Commissioner said the operation was extremely important in going after those who fuel violent crime in the capital.
“Sadly there are too many people who go about in some parts of London feeling that it’s sensible, the right thing for them to do, to carry a weapon.
“Obviously it’s not, firstly it’s against the law, secondly they’re very likely to get killed themselves and thirdly we’re out there and we’re looking for them and we will lock them up if we possibly can.”
The Commissioner said the latest operation has been designed to dismantle a long-standing criminal gang.
“The group that we are going out to arrest tonight contains several very violent people. They are suspected of a large scale conspiracy to supply crack cocaine and heroin.
“It appears they’ve made an enormous amount of money out of that.
“They exploit younger people in their drug dealing, so we need to get them arrested and in so doing we will disrupt the drugs market but more importantly we will get some very violent people locked up and make west London a bit safer.”
Across the UK, violent crime is up around 20% on the previous year.
In London, the last few weeks have seen a spike in murders, particularly fatal stabbings.
This month, the murder rate in the capital overtook the rate in New York for the first time since records began.
On top of the number of deaths, many more have been injured in knife attacks.
One of those hurt last week was just 13 years old – many of the victims and perpetrators are teenagers.
Commissioner Dick said the public were fully behind her officers.
“We are getting an awful lot of support from the public and I think people have been shocked by the events of the past few weeks and in particular young lives lost.
“Everywhere my officers go, people come up to them and say ‘good to see you here, please carry on, please arrest people who’ve got knives and guns’ and we will do that.”
The London operation comes just days after the Government launched its Violent Crime Strategy, aimed at cracking down on offenders and addressing many of the drivers of violent crime.
Home Secretary Amber Rudd vowed to do “whatever it takes” to make Britain’s streets safe when she unveiled plans on Monday.
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The strategy is led by a new Offensive Weapons Bill that aims to make it particularly hard for young criminals to arm themselves.
Those arrested in this latest police operation have been taken to several London police stations for questioning.