Detectives are appealing for information after a man exposed himself to a woman in front of a house.
A man approached the window side on, exposed himself and continued to touch himself inappropriately.
His face was not visible during the incident, which happened on Devonshire Street in Accrington.
It is believed he then ran off in the direction of York Street.
The incident happened at around midnight on Friday, June 27 and follows around half a dozen similar exposure incidents in the Accrington area over the past 12 months.
DC Jo Munro, from Eastern CID, said: “This was very unnerving for this lady and we are very keen to trace the person involved as soon as possible.
“There was a similar offence in this area 12 months ago, so we need the public’s help to find this man and stop it from happening again.
“If anyone has any information that they think might help, if anyone has seen either anything similar or have seen anyone acting suspiciously in the area then please call us.”
The man has been described as being of a stocky build with a large stomach. He was wearing a black quilted or padded jacket.
Anyone with information can call police on 101 quoting reference number 0010 of June 28.
