A 26-year-old man has been stabbed on King Street in Bathgate.
Police officers and two ambulance crews rushed to the scene and the man was taken to Edinburgh Royal Infirmary.
A Police Scotland spokeswoman said: “Police in West Lothian are currently in attendance following an assault in King Street, Bathgate.
“The incident happened around 1.45pm on Tuesday, December 13.
“A 26-year-old man has sustained a serious injury.
“He was treated by the Scottish Ambulance Service at the scene and has now been taken to the Edinburgh Royal Infirmary for treatment.
“Enquiries into the full circumstances are ongoing. Anyone with information is asked to contact Police Scotland on 101.”