Police are on the hunt for a man who exposed himself and committed an indecent act on a bus from Watford to Hemel Hempstead.
The incident happened between 7pm and 7.10pm on Monday, September 17 on the number 550 bus from Watford to Hemel.
The man is described as white,in his mid-to-late 20s, and of slim build. He was wearing a dark brown parka style coat, with a hood which did not have a fur lining, and jeans.
He is believed to have blue eyes which are described as being very close together.
PC Jay Akhtar, investigating, said: “I am appealing to anyone who may have been on this bus travelling to Hemel Hempstead who may have information to come forward.
“I am also appealing to anyone who may have witnessed the incident taking place, to come forward. We are determined to catch this man.”
Anyone with information can contact PC Akhtar on 101 or alternatively call Crimestoppers anonymously on 0800 555 111.