Detectives are hoping to track down a potential witness after a man let off a fire extinguisher in a Blackpool supermarket.
Police have issued a CCTV image of a woman they believe was sprayed with water by the man and have urged her to get in touch.
The incident took place in Iceland, on Topping Street, on November 18 and officers are hoping the woman may have useful information.
Police said they have tried unsuccessfully to identify the woman and are hoping she, or someone who recognises her, will contact them.
Det Con Duncan Worsley said: “The lady in question was sprayed with water by a male using a fire extinguisher.
“I need to trace her and would like to hear from anyone who recognises her.”
Anyone with information is asked to contact Det Con Duncan Wormsley on 101, quoting log reference LC-20131118-0886.