A man dragged a woman to the ground and sprayed her face with chemicals in a “traumatic” daylight assault which left her struggling to see.
The 45-year-old woman had been walking with her young son and two dogs in Livingston when the attacker grabbed her from behind and pulled her to the ground.
Her attacker, who spoke with a Glaswegian accent and was wearing a grey top, then sprayed her in the face with an “adhesive-type” substance that temporarily blinded her.
She was later treated at St John’s Hospital in the town after the incident but is not expected to suffer any lasting injuries.
The incident happened in a wooded area between Almond Court and Stevenson Court in the Craigshill area of Livingston on Monday at around 2.15pm.
Officers are now urging witnesses to get in touch to help the investigation.
Police Constable Stuart Ritchie said: “This was a traumatic incident for the victim and her family and we are pursuing all possible lines of inquiry to find the perpetrator.
“We have recovered the offending item and are appealing for anyone who saw the incident, or any suspicious behaviour in the area at the time of the incident, to come forward.
“Likewise, if you know who this man is, please help us keep people safe and get in touch.”
Concerned local residents took to Facebook to speak of their concerns about crime in Livingston.
Trisha Johnstone posted: “What is this place becoming, now you can’t even take your kids and dogs out on a nice day without constantly looking over your shoulder or being worried sick if your kids are playing in the park even just across the road.”
And Elyse Brown said: “The attack itself is awful enough, but in front of her son? What a despicable person.
“Hope he is found very soon and the lady and her wee boy recover.”
Isolated spray attacks such as the incident on Monday have been relatively rare to date in Scotland.
In December, a woman was arrested in connection with an alleged pepper spray attack at Chalky’s nightclub on the Capital’s Picardy Place.
Witnesses reported that the club had to be evacuated but staff insisted this it was contained to the smoking area outside.
One person was treated at the scene by ambulance crews and one witness described the scene as “pandemonium.”
And in April last year, police in Glasgow launched a manhunt after a teenage girl and her friends were attacked with CS gas spray after she rejected his advances.
The five women, aged between 19 and 51, suffered irritation to their eyes and skin and were taken to hospital as a precaution.
Anyone with information about the Livingston incident should contact Police Scotland on 101 or Crimestoppers anonymously on 0800 555 111.