Police said a man in his 50s stopped a black Volkswagen Polo in Benkhill Drive, yards from Bedale School, at 3.30pm on Saturday (June 28).
He then performed a lewd act, which was seen by a ten-year-old girl, before driving off towards Fitzalan Road.
At 12.25pm on Sunday in Mowbray Road, Catterick Village, the driver of a black Volkswagen Polo stopped by a young girl and indecently exposed himself.
Although left very upset, neither of the girl was physically uninjured.
Detectives said they were linking the incidents as the description of the suspect and his vehicle matched closely.
Police and community support officers are undertaking extra patrols in the area to reassure residents.
The man is described as having a tanned and wrinkled complexion, with short black hair, which is greying.
He was wearing rectangular silver framed glasses and possibly a short sleeved top.
Anyone with information should call police on 101, email email@example.com, or call Crimestoppers, anonymously, on 0800-555-111.