A 17-year-old boy and a 21-year-old man have been arrested on suspicion of possession with intent to supply Class A drugs after police raided a property.
It is believed the Hemel Hempstead address, which was home to a vulnerable adult, was being used by gang members for drug dealing purposes.
Operation Mantis, carried out by police forces across the country, targeted individuals with links to organised crime and drug supply networks.
Detective Chief Inspector Tracy Pemberton from Hertfordshire Constabulary’s Operation Mantis team, said: “We joined police forces across the country taking part in the week of action to target those who are involved in County Lines activities.
"These criminals set up their operations in the homes of vulnerable people and bring violence, drugs and crime to local communities.
"Young and vulnerable people are often the ones who suffer the most, being drawn into criminal activities, drugs and even sexual exploitation."
“We have made a significant impact on the County Lines networks operating in Hertfordshire over the last year, significantly disrupting gang activities and seizing large quantities of drugs and cash during these operations."
If you suspect that a property in your area is being used for criminal activity or you believe that someone you know is being exploited or coerced into crime, contact police on 101
If you are part of a gang or believe you are being coerced or exploited by criminal gang members you can get help and advice at www.fearless.org
Or, you can contact the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111