Fifteen people have been arrested on suspicion of drug offences after a series of raids by police in and around Braintree in Essex and London.
More than 50 officers and three drugs dogs were involved in raids on 15 properties.
The people arrested were held on suspicion of drug offences, said an Essex Police spokesman.
Police said seven have been with supplying a Class A controlled drug - either heroin or crack cocaine.
The raids took place on Wednesday morning.