More than 430 police officers launched simultaneous dawn raids today in a crackdown on drug dealers.
The operation in London came after about 40 ounces of crack cocaine was seized in one of Britain's biggest undercover stings, police said.
Scotland Yard officers posing as drug dealers grabbed 1.1kg of the class A drug in an operation in Brent, north west London, last night.
Three men were arrested as they handed over a carrier bag filled with wraps of the drugs with a total street value of between £80,000 and £100,000.
The bust was the opening salvo of a series of raids across London targeting wholesale dealers in cocaine and heroin.
The move, codenamed Operation Soto, was the culmination of 18 months of work gathering information about several criminal networks.
Police search teams seized quantities of cash, drugs and stolen property as they conducted searches at the addresses.
Superintendent Matthew Gardner, who was responsible for the operation, said the raids will have a "ripple effect" across London and potentially nationwide.
He said: "This is the result of 18 months of hard work. Today will have a significant impact on crime, not only in north west London but across the city.
"We will be disrupting organised criminal networks and drug suppliers across London. We have visited more than 15 addresses this morning.
"These addresses were hit simultaneously and there will be a ripple effect across London."
Mr Gardner added that more than 100 charges are likely to be brought against those held today.
He said up to 19 people will be arrested, including some of those at the top of the drug hierarchy who have evaded detection until now.
Hundreds of officers, including members of the territorial support group, specialist detectives, dog teams and firearms officers gathered at the Metropolitan Police's Hendon training base in the early hours.
Teams of officers were handed briefing packs including information about their target addresses and the suspects they should expect to find.
Officers have spent months gathering information, including surveillance photographs and CCTV footage of those suspected of being involved in the sale of drugs to street-level dealers.
At one address in Eton Grove, Kingsbury, police found six people living in a large terrace property.
Neighbours woke to find a large group of police wearing riot equipment smashing down the door of the property with a pneumatic tool.
One man, a Romanian, was arrested on suspicion of supplying class A drugs and immigration offences.
Other raids took place in Haringey, Edmonton, Hounslow, Bromley, Harrow, Barnet and Southwark.
Chief Superintendent Mark Toland, Brent borough commander, said the raids not only tackle drug dealing but other serious crimes such as violence.
He said: "We have disrupted organised criminality. We have reached a high level of people dealing in class A drugs and reduced the risk of armed criminals.
"This sort of operation shows people in the community we are willing to invest time and effort in making a difference.
"Today is the culmination of lots of information from the community and other groups telling us about people who are blighting the communities of Brent and it has led us across London. We have shown them today how we respond to that information."
In total, nine people were arrested this morning but more may be held later today as they are found or hand themselves in, a Scotland Yard spokesman said.Reuse content