Automatic Number Plate Recognition technology has helped catch suspects travelling in and out of the area, while other arrests were made after concerns were raised about a disturbance at property in York.
"County lines" drug dealing refers to cases where urban dealers forcing children to carry drugs to customers in more rural areas.
Early on Thursday a 17-year-old boy from Manchester was arrested on suspicion of possessing class A drugs after ANPR flagged up a vehicle on Tadcaster Road in York, believed to be linked to county lines drug activity. He remains in police custody.
On Wednesday ANPR showed a car believed to be linked to county lines drug dealing travelling out of the area.
It was stopped by officers as it returned to North Yorkshire on the A64 near Bilborough.
The two men inside, a 37-year-old from York and a 34-year-old from Liverpool, were arrested.
The 37-year-old was arrested on suspicion of three burglaries, of being concerned in the supply of class A drugs and fraud by false representation.
The man from Liverpool was arrested on suspicion of being concerned in the supply of class A drugs.
Both were released but remain under investigation.
Last Saturday three further arrests were made following reports of a disturbance at a property in York.
Two 17-year-olds were taken into custody and the 21-year-old was remanded in custody and charged with possessing class B drugs and obstructing the police. One of the 17-year-olds was issued with a caution and the other released without charge.
In a statement North Yorkshire Police said: "Tackling county lines is a foremost priority for North Yorkshire Police and information from members of the public is invaluable in helping us safeguard vulnerable people, disrupt criminal activity and bring the suspects to justice."