A flasher pulled up beside an elderly woman and asked for directions before exposing himself to her on Sunday morning.
He then went on to target three young teenage girls, flashing them as they walked down a street in Northallerton at around 10am.
Police are appealing for information and offering reassurance after the incident, saying they are visiting local schools to offer advice.
“These are shocking and disgraceful incidents, which have naturally left the victims upset,” said Sgt Gary Sellers, appealing for anyone with information to come forward.
“I also need to speak to anyone else who may have been approached in a similar manner and has not yet reported the incident to the police.”
The man is described as white, aged in his late 20s to early 30s with brown spiky hair. He was wearing a light coloured shirt and blue jeans, and driving a blue estate car.