Officers say on Thursday, January 13, at around 12.15pm, on Whitewells Lane, Belper, a man in a black van pulled alongside a 15-year-old girl, wound down his window and shouted to her.
A Derbyshire police spokesperson said: “He then pulled over, got out of his van and began to follow the girl.
"He did not touch her, got back in the vehicle and drove off.
"The man was described as white, in his 30s, of a slim build and was clean shaven. He was wearing a beanie type hat, black shirt and black work trousers.”
Anyone with information should contact police using the non-emergency methods below, quoting reference 220*23698.
Facebook – send a private message to /DerbyshireConstabulary
Twitter – direct message the contact centre on @DerPolContact
Website – complete the online contact form www.derbyshire.police.uk/ContactUs.
Phone – call 101.