One in five arrests made in a police operation targeting "county lines" drug dealers were of children, a force has revealed.
Of 609 arrests made during Operation Gravity in Norfolk in the 18 months up to 5 June, 126 were of children
Norfolk police revealed that of those 126, 49 were charged with drug offences and one with attempted murder.
The youngest were three 14-year-olds charged with supplying Class A drugs, such as heroin and crack cocaine.
In December 2016, the force launched Operation Gravity, a multi-agency "response to an increase in serious violent crime linked to county line drug dealing in Norfolk."
Figures revealed in a response to a Freedom of Information (FOI) request showed 55 of those children arrested were from London, while 45 were from Norfolk.
The remaining 26 were from Essex, Hertfordshire, Suffolk, Surrey, Middlesex, Leicestershire and Teesside.
The National Crime Agency defines a typical "county lines" scenario as a network between an urban hub and a county location, into which drugs, primarily heroin and crack cocaine, are supplied.
A mobile phone line is set up for local customers to call which is controlled by a third party, usually outside of the county.
Often young or vulnerable people are exploited, sometimes with violence, to secure the use of their homes to store and supply drugs and cash, a practice known as "cuckooing".
A Norfolk police spokeswoman said the force was aware of 35 lines operating in the county, although not all would be active at one time.
Details released by police show one child aged 15 was charged with attempted murder, and another as part of a domestic abuse investigation.
Half the 126 children charged with drug offences were aged 17, and one was also charged with possession of an offensive weapon.
Police said of the 126 arrests, a number of cases "remain under investigation."
Officers have shut down addresses in areas such as King's Lynn and Norwich where drug dealing was taking place.
Police said young people arrested were not always charged.
Assistant Chief Constable Paul Sanford said: "We realise that many of the people involved in this criminality are being exploited themselves and police and partners need to support them rather than prosecute."
Penny Carpenter, chair of Norfolk's children's services committee, described county lines as a "blight on our society".
She said staff had been trained to identify and understand the risks of this kind of exploitation.
"We are planning additional work to raise awareness among our foster carers and residential care staff," she said.
Operation Gravity has so far seized tens of thousands of pounds in cash and class A drugs.